The PJS Braindump Landfill

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noreply@blogger.com (PJS) — Sat, 13 Mar 2010 17:20:00 +0000

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Baltimore Impressions, and some Art

noreply@blogger.com (PJS) — Sat, 13 Mar 2010 17:15:00 +0000

As usual, bigger pictures after the original post link.

Goat Eyes

noreply@blogger.com (PJS) — Wed, 03 Mar 2010 18:44:00 +0000

I simply stole this paper and repost it here. Hopefully this dude is too doped to notice.

Eustace P. Toffeynuts III, "Goat Eyes: Satanic ploy, or merely horrific crime against nature?"

Go Canada!

noreply@blogger.com (PJS) — Sun, 28 Feb 2010 23:42:00 +0000

And the medal statistics - from NBC, CBC, and Die Zeit! Interesting ordering :-)

From NBC:

From CBC:

And Die Zeit:

Liberty Lake, Carroll County, MA

noreply@blogger.com (PJS) — Sat, 27 Feb 2010 22:43:00 +0000

As usual, bigger pics in the original post after the click.

Ten Myths of Apple's iPad: 10. It needs Mac OS X

noreply@blogger.com (PJS) — Sat, 27 Feb 2010 22:04:00 +0000

Um. I don't think there is anything more to ask for.

Blackboard, anybody?

noreply@blogger.com (PJS) — Wed, 24 Feb 2010 19:58:00 +0000

Does anybody know anybody who works or worked on distributed blackboard communications architectures?

I have a real-time, high-data-rate, distributed multi-agent system that needs a stable communications infrastructure. I have a strong hunch that a BB would fit the bill... but I don't want to re-invent the wheel, and it seems that my Google and literature searches focus on the wrong keywords.

So I am looking for a solution, preferable an open-source toolkit, that implements such a blackboard.
Any idea, anybody?

SPIE-MI 2010, San Diego, II

noreply@blogger.com (PJS) — Sun, 21 Feb 2010 21:54:00 +0000

I just returned from the SPIE-Medical-Imaging conference in San Diego.
Unlike last time I have been to San Diego, this time I loved the place.
Loved, loved, loved the place.

What a year of Baltimore can do.

(As usual, big pictures after the click to the original post.)

Fraunhofer at Hopkins

noreply@blogger.com (PJS) — Wed, 10 Feb 2010 22:50:00 +0000

After fifteen months of work, the big "D-Day" of final demos has finally come. Lots of Fraunhofer representatives came to Hopkins for two days of presentations, demos, and discussions about the future of the collaboration.

(As usual, bigger pictures after the click.)

Snowstorm, Historic

noreply@blogger.com (PJS) — Wed, 10 Feb 2010 22:15:00 +0000

Low Expectations

noreply@blogger.com (PJS) — Wed, 23 Dec 2009 19:47:00 +0000

The other day, I asked M whether she is sometimes fed up about her students. She said no, she just has low expectations.

Same with flying in the U.S. I didn't even take off for the first leg to Philadelphia, and we're already 15min late.
It's just a farce that the only PA broadcasts are Dept of Homeland Security threat level advisories.
Threat level is orange. Same as always. No news about the delay.

Lost in modulo 360

noreply@blogger.com (PJS) — Sat, 12 Dec 2009 22:01:00 +0000

Finally somebody expressed the reason why I have difficulties to intuitively navigate in America.

(~~If anybody knows who to credit for this, please drop me a note.~~ Tun, thanks for the quote origin.)

LED Abuse

noreply@blogger.com (PJS) — Sat, 12 Dec 2009 21:10:00 +0000

Another fancy application which was news to me (I am not an electrical engineer, but rather a computing "scientist")... one can use LEDs for sensing.

I was made aware of this by two students of ours, wondering how this is achieved. We explored several ideas and finally came up with a concept that probably is exactly how it works in reality: LED as light sensor.

Fancy.

Magnetic Field Torque

noreply@blogger.com (PJS) — Sat, 12 Dec 2009 18:51:00 +0000

Last week, Edward Cheung from the NASA Goddard Space Flight Center, one of the engineers for the Hubble Space Telescope, visited the LCSR and gave a talk. Given that the Space Shuttle is to be retired after the next half-dozen flights, the talk scope changed to focus on the Shuttle technology. However, there were still some interesting details about the Hubble to be learned.

One of these details concerned the actuation of the telescope. As the Hubble has to stay operational for very long periods of time without any servicing missions, it doesn't have thrusters or boosters for orienting the telescope that would use up fuel. Instead, it uses inertial reaction wheel assemblies (that was what I expected), but also magnetic torquers (which was news to me). To keep the rotational speed of the RWAs within certain limits, the telescope can use metal bars that are extended and oriented into the magnetic field of the Earth as the Hubble traverses it, generating eddy currents in circuits through the bars and thus generating torque that turns the whole telescope (EDIT: or maybe not eddy currents, but rather a capacitor is discharged into the rod, cf. the link below?). The proper term seems to be "RWA momentum desaturation".

Properly awesome principle.
(For more info, look here. In fact, one control center for the Hubble is at the Space Telescope Science Institute just down the road, on my morning way to the parking lot.)

Strangely enough, these insights always come in pairs. Today, I saw an automatic tabletop globe in a catalog. Since it was an "organic" catalog (what is called "Öko" in German), it doesn't use batteries for rotation, but instead has a built-in photovoltaic cell. So far, so good; but the interesting part is that the globe sphere is embedded in an outer glass sphere that completely encases it, and there is no axis connecting the two spheres. In fact, the inner globe sphere is suspended in a thin layer of water within the outer sphere. And yet it moves. (10pts for proper quote attribution without googling.)

The catalog description claimed it uses "Earth magnetic field torque". Of course, having read up to here, the reader knows how it works, but I have to admit at first I thought "what a load of bull". Only then did I remember the magnetic torquers on the Hubble. Probably there is a magnetic rod similar to a compass needle mounted inside the globe sphere, and a photovoltaically powered motor inside the sphere torques the globe sphere against said rod. Voila, completely encapsulated torque actuation. Not a bad idea.

First Snow

noreply@blogger.com (PJS) — Sun, 06 Dec 2009 20:20:00 +0000

Saturday, first snow in Baltimore.

Saftiges Nierchen

noreply@blogger.com (PJS) — Fri, 04 Dec 2009 03:05:00 +0000

Hier ist ein Zwischenstand des Nierchenprojekts. Nicht das Ergebnis (3D-B-Mode-Ultraschall) ist entscheidend, sondern das Funktionieren der gesamten Modul-Pipeline bis dahin...

Noise Emissions

noreply@blogger.com (PJS) — Tue, 01 Dec 2009 18:28:00 +0000

When I came to the U.S., I wondered every day how people tolerate the continuous noise everywhere. Loud cars, air conditioners running all the time, trucks big and small on and off the campus... only very rarely is one of those particularly atrocious transport vehicles on the campus replaced by an electric one. Somehow, silence is not a value here.

(In fact, during my last visit to British Columbia in 2008 I invested two or three days just looking for a place that has no other noises but nature itself. It didn't work. Even in the most remote valleys I tried, there was always at least the hum of some distant plane.)

So I wondered whether there is any country anywhere that has noise emissions regulations, any rules that would govern how machines and devices are to be constructed in a noise-minimizing fashion, sanctioning their operation licenses. Indeed, Germany (and probably some other countries, too) has some laws that regulate noise immissions for workers and in habitated areas (workers have to wear protective gear, and home residents can force noise sources to be shut down), but this doesn't protect the average pedestrian on the street. I don't know of any place that has laws that apply to the engineering side of the equation - making devices quiet before they're built, instead of banning loud ones.

Now it seems that even places like Kenia have noticed that people need to be protected from excessive noise levels. I would not be surprised if neither Germany nor other European places, not to mention the U.S., actually cared about or legislated noise reduction in public places.

Breakthrough

noreply@blogger.com (PJS) — Tue, 01 Dec 2009 01:12:00 +0000

Today was one of those rare breakthrough days.

After many months of work, about 90% of the modules on our side of our Hopkins/Fraunhofer cooperation project that I am working on started working together.
The system consists of lots of separate reusable executables that "run anywhere" (meaning on any of our four or five project machines) and communicate with each other using mostly TCP/IP or shared memory. And over the course of the last two or three days, I figured out (with some help) the last remaining stumbling block to get the data constructed that the Fraunhofer people need.

It's about 8:20pm, so that means I can go home early.

Thanksgiving Lab Turkey

noreply@blogger.com (PJS) — Fri, 27 Nov 2009 04:29:00 +0000

What happened around the Thanksgiving turkey that Ioana and Brian invited us for.

As usual, click through for full picture glory.

Week before Thanksgiving

noreply@blogger.com (PJS) — Fri, 27 Nov 2009 04:10:00 +0000

Impressions from the week before Thanksgiving when Matthias came to Baltimore for the project integration testing.

As usual, click through for the slideshow.

Crawling Around with Baltimore Street Rats

noreply@blogger.com (PJS) — Sat, 21 Nov 2009 15:38:00 +0000

Baltimore and rats: They are smart enough (in a non-individual, Darwinian way) to ambush a garbage truck.

And of course there was this giant rat from China news.

Trouvaillen

noreply@blogger.com (PJS) — Wed, 18 Nov 2009 00:34:00 +0000

Tonight, a sudden flash of useless linguistic insight hit me.

The terms "syndrome" (a group of symptoms that consistently occur together), "concurrency" (esp. programs running in parallel), "Mitläufer" (sb. acting without having formed an own opinion), and "also-rans" (a loser in a race) syntactically all have the same components in their own languages - however, obviously their actual semantic meaning is completely unrelated in each!

Fascinating how the same expression evokes different meanings and feelings in different languages.

Then again, "współbieżny" actually means the same as "concurrent". And for some unrelated ridiculousness, check "współdzielić". (And it's almost unbelievable all those terms in the table there not only mean, but actually evoke all their different semantics!)

Culturalities (Siemens and Pizza)

noreply@blogger.com (PJS) — Sat, 14 Nov 2009 04:32:00 +0000

Yesterday, my little boss arranged a visit at Siemens Corporate Research in Princeton, where I had to give a talk. Luckily, the talk was about something that nobody really knew what it should be (meaning I could choose what to talk about). Sadly, I am still new in my field. Luckily, it went somewhat alright.

I learned that the NIH recently changed its scoring table for grant applications. Where they had a 1-to-5 scale before, in 2009 nothing less than a 1-to-9 scale is good enough. However, the first five categories are labeled "exceptional", "outstanding", "excellent", "very good", and "good". It could be a sign of an imbalance. Projects rated less than "outstanding" face a small chance of getting funded.

Today, I committed a cultural mistake. Ordering a chicken-and-green-pepper-pizza-with-soda-combo-number-three-for-here-thank-you, there was enough cash in my wallet (not BE "purse") to cover the check (not "bill") to cover it. Mistake part one was to pay cash in the first place. Mistake part two was to wait for six cents change. I realized this after the cashier closed the counter without returning my change, but it was too late to back out without embarrassment. So I tried to look around in a noncommittal way without moving an inch. Finally he got the hint, reopened the counter and handed over my six cents. Score for the German.

Half-life

noreply@blogger.com (PJS) — Mon, 09 Nov 2009 04:43:00 +0000

It just occurred to me that by now I have spent more than half my life so far with programming (in the loosest sense of the word, probably more like "thinking in algorithms").

If all goes well, the next half will be spent with programming, too.

If this doesn't change the neural connections, then I don't know what could.

(... I still remember very clearly how arrays confused me back in highschool times... using DIM in QBasic in MS-DOS 5.0 - how could many values be stored under the same name? I chose to ignore pointers back then.

It was awesome that some fellow highschool students were actually able to use TurboPascal's "GUI" units.

Later came the magic of callback functions (with pointers!) in C, when programming the Schroeder 2 in XForms (which still look as fugly as they did back a decade(!) ago) kept us awake.

OOP in Java (brand-new back then, a year or two later; I actually ordered a CD-ROM with something like an "IBM WebSphere Java Developer Kit" through mail) was a relief.

Also, I remember vividly how at the turn of the millenium I learned C++ from what is probably the least appropriate tool - Stroustrup's The C++ Programming Language.

All of this happened before the Internet happened in the way I use it for programming today, which means all of this was harder (which means one actually looked up the parameters for printf() in a book).

Still, I grew up in the era after GOTO.)

Autumn ("Fall")

noreply@blogger.com (PJS) — Mon, 09 Nov 2009 01:23:00 +0000

Autumn (also known as "fall" here) in Mt. Washington and Baltimore County.

As usual, click through for the images. (Tekkno, view them in fullscreen. You'll like what you'll see.)