Accepted paper – DEBS 2015 Grand Challenge!!!

This year, we participated to the DEBS 2015 Grand Challenge. Citing from their website:

“The ACM DEBS 2015 Grand Challenge is the fifth in a series of challenges which seek to provide a common ground and evaluation criteria for a competition aimed at both research and industrial event-based systems. The goal of the 2015 DEBS Grand Challenge competition is to evaluate event-based systems in the context of real-time analytics over high volume geospatial data streams. The underlying scenario addresses the analysis of taxi trips based on a stream of trip reports from New York City.”

In our paper, DEBS Grand Challenge: Deterministic Real-Time Analytics of Geospatial Data Streams through ScaleGate Objects, we show how we leveraged our ScaleGate concurrent data structure (more info here) to solve the challenge. We are pretty impressed by our results, we were able to run the given queries and process one year of data (173 million tuples) generated by 43,000 taxis at a rate of approximately 260,000 tuples/second (that is, 1 year of data in approximately 10 minutes!).

You have a link to the extended technical report of our work here.

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Posted in Concurrent Data Structures, Data Streaming, Research, ScaleGate

How to give a good presentation [part II]

After my previous post (here) I want to share some more tips about how to give a good presentation. As mentioned in the previous post, you can find many pages discussing this topic. This time, I am going for a short list of small tips that I think are somehow complementary to the ones you can usually find around.

  1. Put page numbers in your slides. It is much easier to ask “can you go back to slide X?” rather than “Can you go back? One more, one more, one more… OK here!”
  2. Do not hide. Make yourself visible and audible.
  3. Do not stay in the middle, do not cover parts of the projected slides, make sure everyone can see and hear you.
  4. If possible, check the place where you will present. Does the projector work? Do the colors of your presentation look good with the projector you are going to use? Can you point with your finger or do you need a stick or laser pointer?
  5. Look at the people, try to make eye contact, still being “polite”… if someone wishes to do something else, don’t make him/her feel uncomfortable by staring continuously at him/her.
  6. If possible, try to use a set of colors that are easily distinguishable by color-blind people. Also, in your graphs, use different markers (together with different colors) to help people distinguish between different lines/points.
  7. Do not read the slides! If some specific sentence needs to be cited as it is, memorize it.
  8. Do not memorize what you will say during the presentation. You might get interrupted in many different ways. Also, it does not feel very natural when someone is just repeating what he/she memorized.
  9. Do not improvise too much. If you rehearsed many times the presentation, most likely there is no room for improvisation. Also, you might start saying something you think is very clever and realize half way it is not…
  10. Balance the amount of text and the amount of words you spend for each slide. An empty slide accompanied by five minutes of discussion (or a slide full of text accompanied by a short sentence) will most likely make the audience ask itself why are you making you presentation so hard to understand.
  11. Balance the amount of time you spend for each slide, each slide (except for “outline” slides) should get a similar amount of time, most of the time.
  12. Repeat each question before answering it. Someone in the audience might not have heard it, and he/she will not understand your answer without the question. You might not have heard / understood it correctly, so repeat it to make sure you did. Finally, you will also buy some time to think about what to answer..

I hope you find these tips useful. Good luck with your presentation.

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Posted in Master Thesis, Presentation, Teaching

How to give a good presentation [Part I]

In this post (my first post, actually) I want to share some thoughts about how to give a good presentation. As you can see, the title says “Part I”, which implies that there will be more… You can find a lot of pages, posts and videos about this exact topic, my contribution might not be completely new, in this sense. Nevertheless, I discussed these points several times with master students I’m supervising and I wanted to summarise these discussions here in a sort of short list of very general points. I hope you enjoy it.

  1. Make it your presentation. You are going to shape it and you in the first place need to enjoy it in order to have fun while you present it. As mentioned, you can find a lot of suggestions around. They can help you in deciding which fonts to use, which words to avoid, etc… All these suggestions are useful (especially when the audience that will listen to your presentation thinks they are useful!) and you should think about them. Nonetheless, you should not take them as “rules”, especially if you feel you they work against your presentation.
  2. Rehearse, rehearse and rehearse even more. There is no way the audience is going to listen and enjoy your presentation (and most likely understand it) if it looks like you, in the first place, thought it was not worth preparing it properly. How to avoid this? Rehearse a lot! Measure how long it takes, make sure you don’t exceed your time slot. Try it out speaking loudly, do not go through the slides reading them mentally… Try the presentation with friends, ask them which parts are not clear. If it helps, write down what you plan to say for each slide, but don’t read it during the presentation. Also, do not memorize your presentation word by word, you might be interrupted, asked questions, etc… I usually fell I am ready once, after rehearsing the presentation several times with other people, I am ready to present without looking at the slides at all. I know where I am, I know at which point I should switch to the following slide. The only reason I look at the slides is to ensure the projector is still on or to point to some specific parts of them.
  3. The presentation is not the last step of your work. If you worked hard during weeks or months (or years?) and you understand well why your work / your contribution is important, then filling 30 minutes with a nice presentation will be quite easy. How do you achieve this? By working on your presentation right from the start… Can you prepare a 5 minutes presentation stating the problem behind your work, why is it important and also presenting how you plan to solve it and why you will be successful? If you can, and if the audience understands it, then most likely you are ready to start working on it and… guess what! you already have some nice slides you can reuse for you final presentation… Can you find out how short a presentation about some basic concept on top of which your work will be builded can be? If so, then you can probably differentiate between what should go in your “preliminaries” section and what should go in the related work… and you will have even more slides to reuse for your final presentation… and so on…
  4. State your contribution clearly. Despite all your efforts, the audience might not be interested in what you are presenting. Might have a very bad day. Might be distracted by mails and other stuff… We would like all the people in the audience to be completely focused on what we are saying, but that’s probably not going to happen. To a certain extent, this is out of your control. Nonetheless, it is also your responsibility not to get the audience uninterested. How? well… go back to points 1 and 2. At the same time, based on the fact that most likely the audience will at least try to follow you during the first minutes of your presentation, make sure that everyone, right from the beginning, can understand exactly what your thesis is about, why your contribution is important! Don’t hide this in between your slides, don’t let the audience understand it slide after the slide on its own, tell it clearly from the beginning. This point links also to point 5…
  5. Put your audience at ease. Don’t make the audience wonder “How complicated will this presentation be?”, “Will he/she finish in time?” and so on… Tell the audience how your presentation is structured, when you change from Introduction to Preliminaries or Related Work, tell the audience… “I have introduced you the problem and why it is important. Before discussing the design of the proposed solution, I would like to spend 5 minutes covering some basic concepts about this and that”. Might seem unnecessary, but such a sentence is basically saying “If you already know the problem and decided to check mails waiting for something more interesting to listen to, notice that I will now switch to the discussion of topic X” or “If you got the problem and you would like to take a break while I discuss topic X, which you already master, notice that in 5 minutes I will start presenting the design of my system”… and so on…

That’s all for now. As you can see, very general / high level points… I will start preparing some more direct points and post them in the near future.

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Posted in Master Thesis, Presentation, Teaching