Problem Specific Questions

If you have any questions about the competition problem, submit your question to Kamalesh_Somani@CSX.com and Juan.Morales@bnsf.com In fairness to all participants, RAS will publish its Q&A response on website. All participants will receive Q&A document through email as well. If there are any more questions, similar process will be repeated. No questions will be entertained after August 15, 2010.

All Other Questions

All other questions requring organizing committee's attention must be directed to Homarjun.Agrahari@bnsf.com

FAQ

Q1: The Competition website - Section 9, Judging Criteria states that the "Computer program/model" must be submitted. I am considering using proprietary software for the competition, so I wouldn't be able to submit the source code, however I would be able to describe exactly what the program is doing in pseudo code. Would this be allowed, or is source code required? Those participants that cannot submit “Computer program” should submit additional documentation (e.g., pseudocode, progress logs, …) that supports the accuracy of the results described in the report. It is important to highlight that the quality and clarity of the report submitted will be a key factor in determining the winners of the competition. Additionally, the Judging Panel might ask for a solution to another similar instance of the problem to further validate the solution. Judging panel might also ask for a web conference-based demo of the program (software) set-up and run.

Q2: When a locomotive arrives at destination after powering a train, can the remaining fuel still be used for next train in the following trip? Yes, the example in the problem description illustrates this.

Q3: Is there any restriction on the kind of software that can be used (commercial vs. non-commercial, open source vs. proprietary, etc.)? No restrictions. Please refer to Q1 for more information.

Q4: Is there a time limit on the computation of solutions? Also, if two solutions have the same value, will you give preference to the one that takes less time to compute? There is no time limit. The Judging Panel will consider solution times and scalability as one of the factors in determining the winners of the competition.

Q5: Do the refueling amounts (gallons) for locomotives at each yard have to be integer? No, they could be real numbers. The example happens to have integer answers, but we formatted it to show two digits after decimal.

Q6: Will the initial fuel in locomotive be also a decision variable? To illustrate, in the example for the competition, the initial fuel for L1 and L2 are 377 gallons and 2443 gallons respectively. However, the starting yard does not have truck fueling support. Yes, the initial fuel is a decision variable. The locomotives are running in a continuous cycle. The end of the time horizon is connected to beginning of the time horizon to create the cycle. The fuel level is a continuous variable throughout the cycle. In the example shown, the initial fuel was a decision variable.

Q7: Is it correct that when a locomotive arrives at a destination, the fuel level in the locomotive will be counted as the initial fuel for the next trip? Please refer to Q2. Also, it is possible to put more fuel into the locomotive at the origin of a trip, before it leaves for the next trip.

Q8: Given that our final report is limited to 5 pages, I'd rather not waste pages describing the problem. Is it OK to go directly into describing my solution approach and the results and assume everyone knows what is the problem? Problem description is not one of the items explicitly requested on the Competition’s website for the final report. It is up to each team to determine the content of those five pages. We highlight that the clarity and quality of the report is a key factor in determining the winners of the competition.

Q9: In the file Problem.xls worksheet "Train schedule" train T207 looks like a train with 7 stops over 2 days. However in worksheet "Loco Train Assignment Cycle" Engine L207 connects to train T207 on Mondays and train T208 on Tuesdays (one day later). How is this possible if the first train takes 2 days to arrive at its destination? The table below shows these trains (T207 and T208) with their corresponding departure times. Bolded fields show how L207 is originated on T207 and T208 on alternate days.

Q10: Does the fixed $250 per-stop fueling charge apply to all fueling stops (including fueling performed at origin points), or only apply to fueling performed at non-origin stops? Yes, the fixed $250 per-stop fueling charge applies to all fueling stops.

Q11: The fixed contract cost of the fuel trucks is specified as $4000/week each. In the example provided, one fuel truck is used, and is used in each of the two weeks in the problem horizon (days 1-7 and days 8-14) - and is charged as $8000. If a truck were only required during one week in the problem horizon (e.g. days 8-14 only), would the cost be for only that week ($4000), or would it be assumed to have been 'contracted' for the entire two week horizon period and result in a cost of $8000? The trucks are contracted for the entire two week horizon.

Q12: The solution shown in the example problem is an optimal one? Yes, it is optimal.

Q13: The total cost shown in the overall solution (.xls) did not take the fuel before departure in account; does it mean that we can reload for free during the first time step? The total fuel cost is the cost of fuel dispensed in locomotives at any point in time in the horizon. There is no free “reloading” of fuel.

Q14: As quoted on the website: “A report not exceeding 5 pages, normal margins, double spacing, font size of 10. The report must include title page describing the team members, their affiliations, clean and concise description of problem formulation, solution method, and implementation details (Software/Hardware) and results”. Should a title page include concise description of problem formulation, solution methodology, implementation details (software/hardware) and results, too? Is the title page counted as 1 page too? The Title page counts towards the 5 pages of the report. The report content can start at the Title page.