Friday, 30 July 2010

Algorithms for better public transport

It is always pleasant when an operational research project is commented on in the media. I spotted this in Boing Boing, an online blog which I find fascinating and also frustrating. The story is about a research project into better algorithms for timetabling public transport, and has the acronym ARRIVAL, meaning
Algorithms for Robust and online Railway optimization: Improving the Validity and reliAbility of Large scale systems.

ARRIVAL is hosted in Greece (here), but has been an international research project, sadly without UK involvement. It has produced several published research papers, as well as practical solutions to transport problems.

Wednesday, 21 July 2010

EURO XXIV (EURO24) in Lisbon, part 2

I realise that my first blog about the conference was a little negative. Let's look at the good things about conferences.

I met a great number of people, renewing old friendships, and in a few cases, starting new ones. Conferences are great for this, especially if most of the time, you are beavering away in one place, not meeting like-minded people. I have several friends who I have only met at conferences. It is even a good place to see friends from other parts of the U.K.. Of course, one shouldn't really admit that one goes to conferences to meet people; as far as our paymasters are concerned, we go to present our research work and to listen to other people present their research work.

That's the theory. In practice, many of the presenters are there to "Tick the box" of conference presentation. There is not enough time to discuss the material in depth in the sessions. And people work in tight little niches. So the chances are that you won't get many questions that stir new ideas.

But it was good to be part of this conference. Jim Cochran gave an excellent plenary session about teaching O.R. and making it interesting. The best attended session that I went to was on financial optimization and had some good papers. The worst for attendance was on sustainable development ("we are working on sustainable development for developing countries. To calibrate our model, we are using Luxembourg.") A good number turned up to a session on graphs and networks, but fewer were interested in water systems. And in all these, there were interesting models being discussed.

The conference organisers had excellent catering, apart from the reception. Endless coffee, chilled bottled water, fruit juice or squash, and biscuits to eat. Lunch was one of the easiest conference lunches I have known -- huge buffet tables, so very little queueing.

Springer had a demonstration of their touch-screen library, with 200 books available. All could be read and re-read on screen, though I wonder how long before their text books are on an electronic book?

The sun shone; Lisbon is beautiful, though the university campus could do with more effort clearing rubbish and repairing pavements. I wondered why there were so many police on the campus.

Friday, 16 July 2010

Locating emergency ambulances

The ambulance station in Exeter is on the east side of the city. The city is divided by the river Exe, and the bridges across the river form a bottleneck for traffic. Quite often there is gridlock on the roads approaching the bridges.

So the ambulances are deployed away from the station at times of peak traffic. Yesterday, Tina and I were walking by the river and we spotted such a redeployed ambulance parked by the footpath. It made me wonder ... about the policy for deploying ambulances. This one was placed so that it could cross the river, or leave the city to the north and west. In either direction, the response time would be about ten minutes less than if it started from the base station. My wondering focussed on what conditions prompt such deployment. Is it when the traffic is reported to be at a particular state? Or simply at particular times of day? Has anyone worked on this?

I was reminded of the policy of French traffic police that I saw on holiday; they were deployed to busy roads and junctions and set up tables to deal with on-the-spot fines.

EURO XXIV (EURO24) in Lisbon

I spent some time in Lisbon this week for the 24th EURO conference. EURO is the association of national OR societies from Europe (plus those in Israel and Africa). It was based on the university campus, running from the evening of Sunday 11th July and ending late on Wednesday 14th July. For various reasons I couldn't stay for the last day.

As usual, I have come away from the conference with mixed feelings. It was a huge event, with about 2,700 delegates from the European nations and beyond. Many of them were research students presenting their work in a forum related to Operational Research.

As usual, when things went wrong, I stopped to wonder how things could be improved. So here are some general suggestions for any conference ....

1) Learn from the mistakes of other people. Some things go wrong every time, in different details. One of the disadvantages of EURO is that there is insufficient corporate memory. Each conference is arranged without much having beenlearnt from earlier ones.

2) Consider all the bottlenecks in the queues and points of service associated with a conference. Delegates need service with their registration and need to be able to use the conference website to answer a range of questions quickly and without having to go thorugh too many hoops. So the website should be simple to use and comprehensive. Registration on site is the first queue most people encounter and it should be as simple and quick as possible, which means that efforts should be made in advance to make service times as short as possible OR to have lots of people to give service. To complete my registration I needed to join three queues (for my badge, for my confernece bag and papers, for my banquet ticket). If I had gone on the excursion, there would have been another queue. At other events, these queues could be replaced by one. Similarly, catering queues need to be minimised. It doesn't take advanced use of queue theory to work out that 2,000 people gathering for a buffet meal need a lot of service points. 100 servers perhaps?

3) Help the delegates to find their way around. The home team knows its way around the buildings, but everyone from elsewhere doesn't so they need signs that can be found easily and read quickly.

4) Make sure that the rooms are suitable for the meetings. I spent an afternoon in a room directly underneath the waste pipes of the ladies' toilets, so there were regular sounds of flushing. Another session was in a warm room, and the window opened in such a way that the screen was obscured by the frame.

5) For presenters. Do think about what you should put in your presentation. Nobody will take in your equations and constraints with a hundred variables -- my record was seven different subscripts in the equations on one screen. And large tables are too much to take in during a fifteen minute presentation. There is only time for two or three main points, and then these need to be put simply and clearly.

6) Also for presenters. Do rehearse the presentation, and do it with an audience who will be honest with you. Because the presenters come from all over the place, some of them are less fluent in English than the Brits and other English-speaking countries. Going through the presentation several times before will deal with nervousness, and keep the talk to its time slot.

7) For session chairs. Keep strictly to the timetable and follow your instructions carefully. At EURO the majority of sessions lasted 80 minutes with four papers. They were supposed to keep to 15 minutes presentation, and 5 minutes discussion. Chairs were to keep an eye on the time and stop the speaker. That allowed delegates to move between sessions at those 20 minute intervals. And if presenters didn't show up, then there should be a gap, because there could be people switching sessions to hear the talks at their scheduled times. Did this happen? No ... talks over-ran, chairs failed to stop them, and if there were no-shows, they just went on with the next paper.

8) For everyone, especially those with major responsibilities; there is a time and place for everything, and some plenary sessions are not the times for unnecessary announcements and speeches. For many EURO delegates, a lasting memory of the conference will be the description of how to adjust the conference souvenir bag that was given after the conference banquet!