353 lines
16 KiB
Markdown
353 lines
16 KiB
Markdown
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Category: sss06
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Date: Sep 10 2006
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From: "Andrea Censi" <andrea.censi@dis.uniroma1.it>
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Subject: A report about Oxford and the 2006 SLAM Summer School
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Encoding: BlueCloth FlickrHTML
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format: bluecloth>
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inMenu: true
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Let me quote the words of a renowned Oxford scholar:
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> "Life is too important to be taken seriously."
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If you do not wholeheartedly agree with this statement,
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please stop reading this.
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----------------------
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I stayed three weeks in Oxford: one week for the SLAM school and,
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before that, two weeks for an English course. You might ask: why?
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A very good question indeed - "Why I am not on a sunny beach?" -
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I kept asking myself as I walked down the misty alleys of the old town,
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wearing a scarf on August, 16th, and realizing that - maybe - I would not
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need the three pairs of shorts and the swimsuit I had brought.
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Summary:
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1. The Queen's English
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2. The Harry Potter experience
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3. Parsnip, Marmite and the tea conspiracy
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4. The Summer School
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5. Minor open issues in SLAM
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> Appendix: How to offend seven nationalities at once
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`I`. The Queen's English
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----------------------
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It turns out that a course of English at an advanced level is mostly
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about vocabulary and idioms: by the end of the first week I knew seven
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different ways to address a "promiscuous" woman, and I can tell which ones
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are applicable to American and which to British English. It remains to be
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seen how this will benefit my academic writing.
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It was a lot of fun to learn the differences (or, as the teacher put it,
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"to purify my English after years of prolonged unhealthy exposure to American
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media"), which are not only linguistic, but above all in attitude and
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social norms.
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For example, in the US the first question that people ask you is
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"What do you do?" (meaning: "How much do you earn?"), while in England such
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a question would be felt as unnecessary direct and impolite.
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As a rule,
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it is compulsory to exchange comments about the weather, and there is a lot
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of specialized vocabulary for this; the following table might prove handy
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to understand your acquaintance:
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- "It's a lovely day!" = "It doesn't rain"
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- "It's a nice day!" = "It doesn't rain heavily"
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- "What a wonderful day!"="This morning, at 10:13, I caught a glimpse of the sun"
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(the correct answer to any of these is "isn't it?")
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`II`. The Harry Potter experience
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-------------------------
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flickr: http://www.flickr.com/photos/censi/232006603/
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During my three-week stay I tried my best to immerse myself in the English
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atmosphere.
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I went to a place called Oxford Story [3], where we paid £7 to go through a
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painfully slow indoor ride, sat on a mobile school-desk in the dark for 25
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minutes. It is the claustrophobic equivalent of the American Epcot center in
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Disney World.
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At Epcot, I learned that the final goal of all the scientific progress in the
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last three millennia was to let Walt Disney broadcast Snow White using
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Siemens equipment (Siemens sponsored the ride).
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In Oxford, I learned that the glorious University is the repository of all
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human knowledge, and that the English understatement is a legend. At the end of
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the ride, I was amazed that in Italy I had managed to learn to read and write.
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flickr: http://www.flickr.com/photos/censi/232023681/
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Still, one thing the ride did not explain is how the well-educated,
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smart elite students of Oxford can possibly find rowing fun --
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(probably it IS fun, compared to cricket).
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flickr: http://www.flickr.com/photos/censi/232529032/
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I went to a candle-light baroque concert in the Exeter college chapel.
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The ensemble was 75% Asian, all Oxford researchers, and we were given
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a twenty minute speech about the effort they put in the historical
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research of this obscure composer, that they had a microfilm of the original
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manuscript delivered from a German library, that the viola would be played
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in the original style, blah blah blah. Only in Oxford!
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flickr: http://www.flickr.com/photos/censi/232031895/
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I read "The Hobbit" (Tolkien was a fellow of Exeter college) - I discovered
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that the only two peoples in the known and invented universes to have
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the concept of a "second breakfast" are Hobbits and Italians.
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I watched a performance of MacBeth at an open-air theatre.
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I couldn't understand but one sentence, which is worth mentioning:
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"Alcohol provokes the desire, but it takes away the performance"
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Regarding alcohol, England is one of the places where you can't drink if you
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are under 21 (in Italy, at 18 you have decided to quit).
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Young people have their ID checked at the entrance of pubs and in liquor
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stores: that's only a minor annoyance, as they just need to wait outside
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the store for the first Spanish guy passing by that will buy the wine for them
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(and be compensated with just the change - did you keep the penny, Felix?).
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Anyway the guys at the door use the ID checking mostly as a form of flattery:
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"You are 32? I thought you were 20!" is probably the best pick-up line that
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the English can come up with.
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The other characteristic thing is that in English pubs there is no table
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service: you have to walk to the bar and ask by yourself. The first time can
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be confusing: and you can spend quite some time waiting at the table whining
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about the "poor service".
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`III`. Parsnip, Marmite & the tea conspiracy
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---------------------------------------------
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During the first week I was a guest of a lovely 79-year-old lady.
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Working at the University, she made a point of speaking very posh English.
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And she made a point of cooking traditional English food.
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The typical English dish is some meat with two vegetables aside.
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For the vegetables, pick any two in {parsnip, carrot, potato}.
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Don't look in your dictionary for a translation of "parsnip" as probably
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there isn't one. The lady would tell me that in the next-to-last century,
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this famous professor spent years raising the finest crossbreed of Parsnip as
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to finally obtain what is best described as a big white carrot
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with no taste whatsoever [4].
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Nevertheless, the many regional variants give spectacular variety to the
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English cuisine: the two vegetables can be boiled, fried, baked, microwaved,
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or roasted. There exist also exotic twists, in which the vegetables are put
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on top of the meat, or underneath, or even inside.
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In important occasions, the recipes stay the same but gain a French name.
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flickr: http://www.flickr.com/photos/censi/232526897/
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I tried a thing called Marmite, which the teacher sold to me as "the British
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answer to Nutella". It has the aspect and consistency of engine grease, and,
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as far as I know, also the taste is similar (I've never tasted the grease,
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but next time, presented with choice, I'd give it a go).
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The austerity of English food can be explained by the pitiless weather; but
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how can you explain Marmite, if not with alimentary masochism?
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But... there's one thing that is much better in England: tea. Wherever I tried
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it (at the old lady's, at tearooms, at coffee breaks) it was sooo delicious.
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In Italy we don't get the real thing. Why is that? Is this some sort of
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conspiracy orchestrated by the Italian coffee producers? And is it the
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tea cartello which does not allow good coffee to be imported in England?
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`IV`. The Summer School
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---------------------
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If you go for a career in research, in general you don't get much money,
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or fame, and you don't get to rescue the princess either.
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The two benefits that you do get are: playing with very expensive toys
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and the occasional trip in which you meet all sort of people.
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And when you talk with them, it's sort of strange to realize that your
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interlocutor is one of the 5 people - worldwide - that actually care about your
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research theme, and yet the things you have in common end there, as he has
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different culture, race, religion, and while you two happen to agree that Lie
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brackets are an indispensable tool to characterize the propagation of errors
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on the Euclidean group, you have very different answers to the important
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questions about life, the universe and everything. (In these cases I have
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anecdotal proof that it is much better to stick to research talk, and to
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avoid at all costs the kind of jokes that you can find in the Appendix).
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Instead, at this particular school, I would say that the European character was
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clearly perceived, and I enjoyed it -- but whether England is in Europe is a
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delicate matter.
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Here are some impressions of the people.
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* Juan Domingo Tardos (aka Mingo) is the funniest of the bunch, the man you
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want to go partying with.
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He taught us two deep truths about SLAM and life:
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1. The size of your banana matters.
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2. Never under-estimate the size of your lemons.
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I thought: wow, I want to write a paper with "banana" in the title - finally
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some inspiration from the school! I already had big projects for Fig. 1,2
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and a full-page Fig. 3, but after a little googling I found:
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"Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire"[5]
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"Dealing with large bananas" [6].
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I gave up: I cannot beat this last one. And the existence of [6] proves
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once again that SLAM is a solved problem.
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* Paul Newman, the organizer, told us, more than once, that the future of SLAM
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is in long term operation if we want the systems to be reliable.
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(Personally, I disagree: I think that it is possible to build anything at
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the desired level of reliability, given reasonable funding, time, and
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an appropriate number of German engineers)
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* One of the lessons learned in the school is that almost everything has
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already been done by someone else.
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More specifically, most of the things have already been done by
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Durrant-Whyte some twenty years ago, when men were men, CS was electrical
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engineering, master students knew calculus, and Kalman filters ran
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free in the wild lands of Australia.
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* Frank Dellaert is a jolly chap as well, and he does interesting things with
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graphs. As he introduced three different formalisms in the first
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three slides, I regretted not to have put more CS in my curriculum, then
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shut my eyes. Interestingly, at summer schools and conferences, if you close
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your eyes people assume that you are very smart and that you are thinking
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about some new impressive algorithm -- I was just dreaming of a sunny beach.
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* Henrik Christensen has implemented SLAM on the cleaning robot for $45
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in sensors and electronics. It puts things in perspective, especially
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if you consider that I paid £16 for a one-hour coach trip from Heathrow
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to Oxford.
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* Andy Davison is a wonderful person, he tutored the practicals with
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infinite patience. Never did I meet such a knowledgeable, affable,
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and humble person. (Probably he is the kind of person that some day will
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show up at work with automatic guns)
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* Wolfram Burgard - he wins my "best robot" award for the photo of our
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beloved Albert [7].
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* Dieter Fox wins "most nostalgic slide from the 90s": and every time we feel
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the same emotion as the first time.
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* Kurt Konolige reminded me why I bought a Mac.
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* Simon Lacroix - Once we sat at the same table during lunch. While he
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talked with Dellaert, he would send me alarmed glances, the kind of glances
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that you would reserve to a relative returning from death. I wanted
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to ask him why, but then I decided I'd better not to (was I so wasted
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from the night before?).
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* Simon Julier -- he seems very smart, but he lost me between slide #3 and #4.
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I started to be seasick from all those covariance matrices -
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so I muttered to my neighbours: "I wonder whether it still holds in
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higher-dimensional spaces...", then I closed my eyes and was back again on
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the sunny beach.
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* But all in all, the most interesting presentation was the magical show
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that Davide Scaramuzza (who at daytime pretends to work at ETHZ) gave to a
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selected audience after the banquet ([8]).
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It was another confirmation that all the time spent in front of a monitor is,
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in fact, wasted, and all of us should have studied card tricks instead:
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you have NO IDEA of how a girl's face brightens up and her eyes expand when
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she watches a magician.
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`V`. Other minor issues in SLAM
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--------------------------------
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We all know that the most important open problem in SLAM is that there are
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not enough women doing research in the area and coming at summer schools.
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As for the other minor issues, this is the result of asking
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"What is the future of SLAM?" to a random sampling of the participants.
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(the list does not include answers given after 10:00 PM)
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- For 30% of the respondents, SLAM is a solved problem, and we just need some
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German engineers to work out the details of the implementations.
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- Long term operation: make filters that reconsider their decisions at a
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a later time (so not delaying decisions, but explicitly reconsider).
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- Make it robust for real applications: or, your method should work in more
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than one experiment and possibly also outside of your lab.
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- Put more knowledge in SLAM about the environment. Teach your
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filter what is a tree, a road, a mirror so that it can make smarter
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decisions.
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- Active SLAM and SLAM-guided exploration (once we figure out good acronyms).
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- Some boring work is to be done for taking into account linearization errors
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in the already existing results about consistency, sparsity, etc.
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- "Where can I get some real coffee?" (2 people)
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- Methods and representations for real sensor fusion (laser, camera, etc).
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- Do robust stuff with a single camera. Omnidirectional cameras are cool.
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Mix different techniques at different time-scales: visual odometry between
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frames, then stable features, then databases of places to close the loop
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(or don't close the loop at all).
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Appendix. How to offend seven nationalities at once
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--------------------------------------------------
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In Oxford I learned the ultimate rude stereotypical joke -- I think it's
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worth sharing.
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> **Heaven & Hell**
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>
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> *In Heaven*: the policemen are British, mechanics are German, chefs are French,
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> wives are Japanese, neighbours are Dutch, lovers are Italian,
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> and the Swiss organize it all.
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>
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> *In Hell*: the policemen are German, mechanics are French, chefs are British,
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> neighbours are Japanese, wives are Dutch, lovers are Swiss,
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> and the Italians organize it all.
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For related work, see for example [9], [10].
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And here's the research version:
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> **The BEST international research project**
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>
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> - The French do the overall math analysis,
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> - a Chinese refines a ten-line proof of the main Theorem,
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> - the Germans design the implementation,
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> - Japanese undergrads do the actual work,
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> - the British write the paper,
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> - an American gives the presentation,
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> - the Spanish organize the social events,
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> - and the Italians organize the banquet.
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>
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> **The WORST international research project**
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>
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> - The Germans do the overall math analysis,
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> - an American PhD student spends 10 CPU year on his department's 48-node
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> cluster and proves with a Monte Carlo simulation in Matlab that
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> Theorem 1 indeed holds for some values of the parameters,
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> - the French design the implementation,
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> - one Spanish undergrad does the actual work,
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> - the Italians write the papers,
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> - a Chinese gives the presentation,
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> - the Japanese organize the social events,
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> - and the British organize the banquet.
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`:-)`
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Flickr: <http://www.flickr.com/photos/censi/232003838>
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References
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----------
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\[1\] [http://www.spellingsociety.org/news/media/poems.php](http://www.spellingsociety.org/news/media/poems.php)
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\[2\] dde [http://www.flickr.com/photos/censi/236722418/](http://www.flickr.com/photos/censi/236722418/)
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\[3\] [http://www.oxfordstory.co.uk](http://www.oxfordstory.co.uk)
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\[4\] [http://www.botanical.com/botanical/mgmh/p/parsni12.html](http://www.botanical.com/botanical/mgmh/p/parsni12.html )
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\[5\] E. Meijer, M. Fokkinga, R. Paterson. "Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire" (1991)
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[http://citeseer.ist.psu.edu/meijer91functional.html](http://citeseer.ist.psu.edu/meijer91functional.html)
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\[6\] R. Lammel, J. Visser, J. Kort. "Dealing with large bananas" (2000) <http://citeseer.ist.psu.edu/lammel00dealing.html>
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\[7\] [http://www.informatik.uni-freiburg.de/~burgard/](http://citeseer.ist.psu.edu/lammel00dealing.html)
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\[8\] [http://asl.epfl.ch/~scaramuz/cabaret/cabaret.wmv](http://asl.epfl.ch/~scaramuz/cabaret/cabaret.wmv)
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\[9\] [http://www.anth.uconn.edu/faculty/boster/cultvar/euweb/](http://www.anth.uconn.edu/faculty/boster/cultvar/euweb/)
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\[10\] [http://www.infonegocio.com/xeron/bruno/italy.html](http://www.infonegocio.com/xeron/bruno/italy.html)
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