Archive for June 2017

LASER summer school on software for robotics: last call for registration

Much of the progress in robotics is due to software advances, and software issues remain at the heart of the formidable challenges that remain. The 2017 LASER summer school, held in September in Elba, brings together some of the most prestigious international experts in the area.

The LASER school has established itself as one of the principal forums to discussed advanced software issues. The 2017 school takes place from 9 to 17 September in the idyllic setting of the Hotel del Golfo in Procchio, Elba Island, Italy.

Robotics is progressing at an amazing pace, bringing improvements to almost areas of human activity. Today’s robotics systems rely ever more fundamentally on complex software, raising difficult issues. The LASER 2017 summer school covers both the current state of robotics software technology and open problems. The lecturers are top international experts with both theoretical contributions and major practical achievements in developing robotics systems.
The LASER school is intended for professionals from the industry (engineers and managers) as well as university researchers, including PhD students. Participants learn about the most important software technology advances from the pioneers in the field. The school’s focus is applied, although theory is welcome to establish solid foundations. The format of the school favors extensive interaction between participants and speakers.

We have lined up an impressive roster of speakers from the leading edge of both industry and academia:

Rodolphe Gélin, Aldebaran Robotics
Ashish Kapoor, Microsoft Research
Davide Brugali, University of Bergamo, on Managing software variability in robotic control systems
Nenad Medvidovic, University of Southern California, on Software Architectures of Robotics Systems
Bertrand Meyer, Politecnico di Milano & Innopolis University, on Concurrent Object-Oriented Robotics Software
Issa Nesnas, NASA Jet Propulsion Laboratory, on Experiences from robotic software development for research and planetary flight robots
Hiroshi (“Gitchang”) Okuno, Waseda University & Kyoto University, on Open-Sourced Robot Audition Software HARK: Capabilities and Applications

The school takes place at the magnificent Hotel del Golfo in the Gulf of Procchio, Elba. Along with an intensive scientific program, participants will have time to enjoy the countless natural and cultural riches of this wonderful, history-laden jewel of the Mediterranean.

For more information about the school, the speakers and registration see the LASER site.

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Feature interactions, continued

Microsoft Office tools offer  features for (1) spelling correction and (2) multi-language support. They are not very good at working together, another example of the perils of feature interaction.

Spelling correction will by default
when misspelled, but in the case of common misspellings known to the tools it will simply correct words without bothering the user. For example if you type “bagage” it will change it silently to “baggage”. This feature can be turned off, and the list of known misspellings can be edited, but most people use the defaults, as I am assuming here.

Multi-language support enables you to “install” several languages. Then when you type a text it will after a few words guess the relevant language. From then on it can  apply the proper spell checks and corrections.

These features are both useful, and by and large they both work. (The second one is not always reliable. I regularly end up, particularly in Microsoft Word, with entire paragraphs underlined in red because for some inscrutable reason the tool assigns them the wrong language. In such cases you must tell it manually what language it should apply.)

Their combination can lead to funny results. Assume your default language is English but you also have French installed, and you are typing an email in French under Outlook. Your email will say “Le bagage est encore dans l’avion”, meaning “The baggage is still in the plane”. The word “baggage” has one more “g” in English than in French. You start typing  “Le bagage”, but because at that point the tool assumes English it corrects it silently:


Next you type “est encore”:


The  word “est” (is) gets flagged because (unlike “encore”, here meaning “still”) it does not exist in English. When you add the next word, “dans” (in), the tool is still assuming an English text, so it flags it too:


Now you type “l” and when you add the apostrophe, you can almost hear a “silly me, I see now, that’s French!”. Outlook  switches languages and unflags the previously flagged words, removing the red squiggle under the ones that are correct in French:


But that is too late for “baggage”: the automatic respelling of “bagage”, coming from the default assumption that the text was in English, no longer makes sense now that we know it is in French. So the word gets flagged as a misspelling. You have to go back and correct it yourself. That is frustrating, since you typed the correct spelling in the first place (“bagage”), and it is the tool that messed it up.

This bug hits me often. It is indeed a bug, which can introduce misspellings into a text when the user typed it correctly. When the tool recognizes that the text is in another language than the one assumed so far, and performs a second pass over the part already analyzed, it should reconsider both the words previously flagged as misspellings but also those previously corrected. There is no justification for doing one and not the other.

Among the world’s most momentous problems, this one does not rank very high. It is only a small annoyance, and only a tiny set of people will ever notice it. But it provides another illustration of how tricky it is to go from good individual features to a good overall design.


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The perils of feature interaction

One of the most delicate aspects of design is feature interaction. As users, we suffer daily from systems offering features that individually make sense but clash with each other. In my agile book [1] I explained in detail, building on the work of Pamela Zave, why this very problem makes one of the key ideas of agile methods,  the reliance on “user stories” for requirements, worthless and damaging.

A small recent incident reminded me of the perils of feature interaction. I used my Lenovo W540 laptop without power for a short while, then reached a sedentary location and plugged it in. Hence my surprise when, some hours later, it started beeping to alert me that it was running out of battery. The natural reactions — check the outlet and the power cord — had no effect. I found the solution, but just in time: otherwise, including if I had not heard the warning sound, I would have been unable to use the laptop any further. That’s right: I would not have been able to restart the computer at all, even with access to a power outlet, and even though it was perfectly functional and so was its (depleted) battery. The reason is that the problem arose from a software setting, which (catch-22 situation) I could not correct without starting the computer [2].

The only solution would have been to find another, non-depleted battery. That is not a trivial matter if you have traveled with your laptop outside of a metropolis: the W540 has a special battery which ordinary computer shops do not carry [3].

The analysis of what made such a situation possible must start with the list of relevant hardware and software product features.


  • HA. This Lenovo W series includes high-end laptops with high power requirements, which the typical 65-watt airplane power jack does not satisfy.
  • HB. With models prior to the W540, if you tried to connect a running laptop to the power supply in an airplane, it would not charge, and the power indicator would start flickering.  But you could still charge it if you switched it off.
  • HC. The W540 effectively requires 135 watts and will not take power from a 65-watt power source under any circumstances.


  • SA. The operating system (this discussion assumes Windows) directly reflects HC by physically disabling charging if the laptop is in the “Airplane” power mode.
  • SB. If you disable wireless, the operating system automatically goes into the “Airplane” power mode.
  • SC. In the “Airplane” power mode, the laptop, whether or not connected through a charger to a power outlet of any wattage, will not charge. The charging function is just disabled.
  • SD. One can edit power modes to change parameters, such as time to automatic shutoff, but the no-charging property in Airplane mode is not editable and not even mentioned in the corresponding UI dialog. It seems to be a behind-the-scenes property magically attached to the power-mode name “Airplane”.
  • SE. There is a function key for disabling wireless: F8. As a consequence of SB it also has the effect of switching to “Airplane” mode.
  • SF. Next to F8 on the keyboard is F7.
  • SG. F7 serves to display the screen content on another monitor (Windows calls it a “projector”). F7 offers a cyclic set of choices: laptop only, laptop plus monitor etc.
  • SH. In the old days (like five years ago), such function keys setting important operating system parameters on laptops used to be activated only if you held them together with a special key labeled “Fn”. For some reason (maybe the requirement was considered too complicated for ordinary computer users) the default mode on Lenovo laptops does not use the “Fn” key anymore: you just press the desired key, such as F7 or F8.
  • SI. You can revert to the old mode, requiring pressing “Fn”, by going into the BIOS and performing some not-absolutely-trivial steps, making this possibility the preserve of techies. (Helpfully, this earlier style is called “Legacy mode”, as a way to remind you that your are an old-timer, probably barely graduated from MS-DOS and still using obsolete conventions. In reality, the legacy mode is the right one to use, whether for techies or novices: it is all too easy to hit a function key by mistake and get totally unexpected results. The novice, not the techie, is the one who will be completely confused and panicked as a result. The first thing I do with a new laptop is to go to the BIOS and set legacy mode.)

By now you have guessed what happened in my case, especially once you know that I had connected the laptop to a large monitor and had some trouble getting that display to work. In the process I hit Fn-F7 (feature SG) several times.  I must have mistakenly (SF) pressed F8 instead of F7 at some point. Normally, Legacy mode (SI) should have made me immune to the effects of hitting a function key by mistake, but I did use the neighboring key F7 for another purpose. Hitting F8 disabled wireless (SE) and switched on Airplane power mode (SB). At that point the laptop, while plugged in correctly, stopped charging (SC, SD).

How did I find out? Since I was looking for a hardware problem I could have missed the real cause entirely and ended up with a seemingly dead laptop. Fortunately I opened the Power Options dialog to see what it said about the battery. I noticed that among the two listed power plans the active one was not “Power Saver”, to which I am used, but “Airplane”. I did not immediately pay  attention to that setting; since I had not used the laptop for a while I just thought that maybe the last time around I had switched on “Airplane”, even though that made little sense since I was not even aware of the existence of that option. After trying everything else, though, I came back to that intriguing setting, changed to the more usual “Power Saver”, and the computer started to charge again. I was lucky to have a few percent of battery still left at that point.

Afterwards I found a relevant discussion thread on a Lenovo user forum.

As is often the case in such feature-interaction mishaps, most of the features make sense individually [4]. What causes trouble is some unforeseen combination of features.

There is no sure way to avoid such trouble, but there is a sure way to cause it: design a system feature by feature, as with user stories in agile development. The system must do this and it must do that. Oh, by the way, it must also do that. And that. User stories have one advantage: everyone understands them. But that is also their limitation. Good requirements and design require professionals who can see the whole beyond the parts.

A pernicious side of this situation is that many people believe that use cases and user stories are part of object-oriented analysis, whereas the OO approach to requirements and design is the reverse: rise above individual examples to uncover the fundamental abstractions.

As to my laptop, it is doing well, thanks. And I will be careful with function keys.

Reference and notes

[1] Bertrand Meyer: Agile! The Good, the Hype and the Ugly, Springer, 2014,  Amazon page: here, book page: here. A description of the book appeared here on this blog at the time of publication.

[2] Caveat: I have not actually witnessed this state in which a plugged-in laptop will not restart. The reason is simply that I do not have an alternate battery at the moment so I cannot perform the experiment with the almost certain result of losing the use of my laptop. I will confirm the behavior as soon as I have access to a spare battery.

[3] It has been my systematic experience over the past decade and a half that Lenovo seems to make a point, every couple of years, to introduce new models with incompatible batteries and docking stations. (They are also ever more incredibly bulky, with the one for the W540 almost as heavy as the laptop itself. On the other hand the laptops are good, otherwise I would not be bothering with them.)

[4] One exception here is feature SB: switching wireless off does not necessaril y mean you want to select a specific power mode! It is a manifestation of the common syndrome  of software tools that think they are smarter than you, and are not. Another exception is SE: to let a simple key press change fundamental system behavior is to court disaster. But I had protected myself by using legacy mode and was hit anyway.

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Об опыте иностранца, говорящего по-русски

Когда-то очень давно великий советский ученый Андрей Петрович Ершов мне рассказал следующий анекдот. Действие происходит в московском метро. Стоит бабушка, а за ней высокий студент из Университета Имени Патрицы Лумумбы. Он стучит ей по плечу, она поворачивает голову, видит его, вскрикивает (она никогда в жизни не видела Африканца), и падает в обморок.

Другие пассажиры успокаивают ее («ничего страшного, он такой же человек, как и мы!») и она постепенно приходит в себя. Африканский студент объясняет: «Прошу прощения, я только хотел Вас спросить: Вы на следующей выходите?».

Она испуганно смотрит на него и опять падает в обморок, крича: « Ах! Говорит!».

Ершовский анекдот точно описывает ежедневный опыт иностранца в России, который сносно владеет русским языком; но все всегда и везде тотчас же узнают, что он иностранец. Никто и не полагает, что такое существо способно произвести толковые звуки. А если он, вопреки всем ожиданиям, открывает рот и что-нибудь говорит в своей имитации русского языка, выражение на лице собеседника сразу же меняется в испугу : «Ах! Говорит!».

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The coming European renaissance

The unspeakable in flight of the uneatable. One of the sad scenes of today’s Europe does not even take place in continental Europe, and does not even look sad. It happens every Friday afternoon at London’s Saint Pancras railway station as young expats from the continent joyfully board the Eurostar train on their way home for the week-end. They are all smiles, but the scene is nonetheless heartbreaking: why did these young and energetic graduates, some of the best the continent’s universities have trained in science, technology, finance and entrepreneurship, feel compelled to cross the Channel to deploy their talents? Sure, it is a great idea to try your luck abroad, but then the flux should be symmetric. Today, it is largely one-way.

That flux will stop. With Brexit, Britain has condemned itself to irrelevance. What a mournful end for one of the greatest civilizations in the history of humankind, which gave us both Newton and Darwin, as well as habeas corpus and the concept of individual liberty [1]! Faced with an obvious choice between grandeur and decline, a majority of Britons voted for decline and there is no going back. The word “Brexit” was coined to mean “British Exit”; there is no mention of Europe in it, an appropriate omission since Britain did not really choose to exit Europe, it chose to exit the modern world. The best that can now happen to it is that Britain keeps its oil and becomes something like Norway. Even that is not certain; the Scots may decide otherwise.

For a while I felt awfully sorry for my British friends and colleagues. They do not deserve this. Of course they did not vote for Brexit — no one with an ounce of reason did — but they have to suffer the consequences. On the other hand things may not be so bad in the long term. Many of them are Europhiles already; they will just move to more auspicious climes. Already the British are pumping up Paris real estate [2].

In the US, the tragic buffoonery goes on. Some days are more buffoon, others more tragic, but the destruction of one of the most successful societies on earth has started, and even though a majority of Americans are horrified with what is happening to their country the movement seems impossible to reverse because of the particular political system to which the US has now arrived. We may call it gerrycracy: democracy bridled by gerrymandering  (plus the Supreme Court). This system, although a recent invention in its current form, is designed to be self-reproducing, a phenomenon compounded by the evolution of the dominant party, which seems to have lost any sense of decency. The country’s greatness will not disappear in one day or one year; all that the world admires in the US, from Stanford and Harvard and MIT to the Metropolitan Museum and the Metropolitan Opera and the New York Review of Books to the Jet Propulsion Laboratory and Silicon Valley and Tesla is still up and churning. But the trajectory is set: downhill.

The programmed self-immolation of these two intellectual and economic powerhouses, depressing as it is, provides an extraordinary opportunity for Europe [3]. Here is a mosaic of democracies sharing an acute determination to do everything in their power to ensure that the horrors of their past will never occur again. People in Europe (not just the French) complain all the time, but they have, overall, the best deal in the entire world. Bewildering cultural riches, a non-extreme climate at least so far, decent economic standards, good-quality and largely free education, well-functioning basic services, a social safety net, tolerance for minorities, recognition of private enterprise, the rule of law… Where else on earth?

Europe has its challenges. Those of us who admire Macron’s bravado in inviting (in English) US scientists and engineers to come to France, and who also know how things work in European universities and business, are a little nervous. Convincing as the appeal is, it requires a serious redesign of the European university system and a concerted attack on the bureaucratic shackles and societal pettiness that stifle European creativity at all levels. It is doable. If someone like Macron could overcome the assault of demagogues and defeatists from the left and the right to get elected, he can start, with his counterparts in other European countries, to address the structural problems that hinder European progress. The context is right: the main countries have adults at the helm (in Germany this will remain true whether we get Merkel or Schulz) and the winds of optimism are blowing again. While Europe faces other major issues, present in the headlines everyday and hard enough on their own, the main challenge is economic: Europe needs to get richer. It is remarkable how much more smoothly a society functions, and how much happier people sound, when there is enough money going around. Just look at Switzerland. Macron and some of his international colleagues are the kind of strong and pragmatic leaders who understand this goal. They will also benefit, if Europe does not falter in its collective negotiating strategy, from a welcome windfall: the many billions that the UK will have to pay to disengage from its obligations. They should invest that money where it can make a difference: not the traditional European pork barrels, but science and technology, where it will catalyze Europe’s growth and wealth.

While the US and the UK are wasting their time, energy and money on non-problems, unimportant problems and self-inflicted problems, on building Maginot walls, on investing in technologies of the past and on closing themselves off from the sources of their own future, Europe should work on what matters. It should, and I think it will, at least as long as the King Ubu in the White House doesn’t get us into WW3 in response to some disagreeable tweet.

In forthcoming articles I will provide more detailed analyses of the various points sketched here. And yes, I know this venue started out as a technology blog and I will continue to talk about void safety, effective concurrent programming and how to verify programs. But the stakes are too high for scientists and engineers to stay neutral. Through what we know, see and understand, it is our duty to help Europe and with it the rest of humankind.

It could just work. I cannot wait for the scene at Paris’s Gare du Nord, a few years from now, on the typical Friday evening: lads and gals from London and Birmingham and Stoke-on-Trent, eager to go home and get their hands on some fish and chips, but ready to return on Sunday night to resume their cheerful part in the new European renaissance.



[1] A remarkable  symbol of personal liberty is Blonde’s answer to Osmin, the head of the Janissaries who attempts to subdue her in Mozart’s Abduction from the Seraglio (from 1782, seven years before the French revolution!): Ich bin eine Engländerin, zur Freiheit geboren (I am an Englishwoman, born to freedom). Blonde is not even the opera’s heroine but her servant.

[2] Brexit and the “Macron effect” are attracting the British to Paris (in French), in Le Monde, 31 May 2017, available here.

[3] Britain having officially thumbed its nose at Europe, we should from now on use the term to denote the continental part.

[4] Macron’s speech is available here, particularly from 1:34.

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