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Comment Re:Why? (Score 1) 73

Easy answer:

Some of those fjords are 200+ meters deep at the narrowest points near the outlet, i.e. where you would want to build a bridge/tunnel/submerged tube.

We already use tunnel crossings underneath a lot of shallower crossings, and several not so shallow, like the one about half an hour south of Oslo, near Drøbak:

The tunnel is 7-8 km long even though the fjord is less than a km wide at that point, the extra distance was required in order to keep the incline at or below the (highway) maximum allowable 7%. The problem is that 3+ km of 7% downhill (requiring a lot of braking for a heavy rig) and then 3+ km of steep uphill is sufficient to cause trailer breakdowns more or less every week. We also get truck/bus fires inside tunnels almost every year here in Norway.

I am currently in the Hvaler archipelago on the south-east corner of Norway, a few km from the Swedish border. The main/only road leading to the largest of the many islands is nearly 4 km long and still needed 10% descent/ascent angles to get deep enough.

This is dangerous enough to force the entire tunnel to close down whenever a truck with dangerous/inflammable cargo (i.e. gasoline/LPG/diesel) needs to pass through.

Comment 3 months is the rule here... (Score 2) 765

I have worked previously in the US but I must say that I prefer the Scandinavian setup we have here (in Oslo, Norway):

You must give notice, typically 3 months from the end of the current month, and if your employer wants to fire you they must also give similar notice, i.e. 3+ months.

For older/more senior employees the notice interval increases for the employer, up to 6+ months for a worker in her sixties.

What this means is that both parties know that they have to stay civilized.

In a case of possible conflict of interest it is common for these long notice intervals to be negotiated down, sometimes to zero. I.e. when I considered leaving my then job to go work for a major client of ours, my CEO told me that I would be allowed to leave immediately. (I didn't accept that offer so the question became moot.)

OTOH, I have been in a situation where I effectively quit immediately, but that was only an in-house transfer:

I went to my yearly performance review after a year of effectively being my own boss, but I still needed someone to be responsible for signing my time sheets and travel expenses etc, so the same person was doing my review.

The guy started the review by saying "Terje, as we both know you aren't really working for me so I had to go out and ask a few of the people you have been helping over the last year, and according to them it sounded like we should put a statue of you outside the corporate headquarters!"

OK, so at this point I was thinking 'This is going very well!' but then he continued "- but since I have a limited sum to distribute for pay raises I have reserved that for my own people and given you a negative evaluation so you will not be getting anything this year".

At this point I stood up, saying "I don't think we have anything else to talk about", left the room and went directly to HR telling them they had better find me a new boss to report to.

Terje

Comment Re:The usual way (Score 1) 515

That was indeed the usual way:

Personally I had written algorithms and used them on paper for several years when I started university in 1977 (an MSEE program) and got a compulsory PROGRAMMING 101 class. By the time week two or three came around and we got the second programming assignment I had a wonderful lightbulb moment: "Yes! I can do this! I can calculate anything now"

In 1982 I got a couple of IBM compatible PCs and had to start writing asm code almost at once, because there were no hardware drivers at all, but the result was that I understood everything that happened in those machines, in particular how to make really small & efficient code so that a 4.77 MHz machine with a 4-clock (byte) bus cycle could actually d something useful.

The years since then has been spent filling in all the gaps, i.e. all the stuff that I didn't realize I didn't know.

In the meantime I've been lucky enough to be involved with lots of interesting stuff, like helping to optimize the world's first SW DVD player, the core assembly code for Quake, one of the AES candidates, Intel's reference h.264/CABAC decoder and many more. I've also been part of the NTP Hackers team for 15-20 years now, and I'm also writing FP emulation code for the Mill cpu (millcomputing.com, a cpu with a belt instead of registers).

Conclusion?

I've learned to program by being intensely interested in it for almost 40 years now.

Anyone who became a "programmer" simply because it seemed like an easy way to make a living is more likely to be a part of the problem instead of a part of the solution.

Terje

Comment IPX LAN gaming at Novell (Score 3, Interesting) 351

I went from Norway to Utah in 1991, there I met John Cash who used to spend a night every week or two playing Doom deathmatch.

When he fired up his network sniffer he discovered that all LAN communication took place over IPX global broadcast, i.e. they would traverse all routers and end up at every single one of the 6000+ PCs on Novell's internal network!

John found the email of a guy at iD who seemed to know something (John Carmack :-) ) and sent off a message stating basically that the networking code sucked.

A few days later he got a reply: "Sorry about that, we outsourced that development. Here is the source code, please fix it!"

This was "put up or shut up" time, so Jiohn rewrote that code over the next couple of days and returned it.

A couple of years later Cash was hired by Carmack and Abrash as the third core programmer on the Quake team.

Terje
PS. I personally sucked at Doom, but since I was involved with Quake asm development from the beginning I became significantly better at that series.

Comment Re:Europe (Score 5, Informative) 160

That's the key question: Unless you have an available open access frequency band, this standard is just wishful thinking instead of a new product.

The current allocations in Europe (http://www.erodocdb.dk/docs/doc98/official/pdf/ERCRep025.pdf) covers all of 890-942, 942-960 and 960-1164 MHz, with usage mostly cell phone, radio-navigation and broadcasting.

Terje

Comment Why didn't they optimize the new generator? (Score 1) 136

The new 128-bit generator is shown as this piece of code, using a pair of 64-bit state variables:

uint64_t state0 = 1;
uint64_t state1 = 2;
uint64_t xorshift128plus() {
    uint64_t s1 = state0;
    uint64_t s0 = state1;
    state0 = s0;
    s1 ^= s1 > 17;
    s1 ^= s0;
    s1 ^= s0 >> 26;
    state1 = s1;
}

The absolute minimum latency of that code is 8 clock cycles, assuming that the two initial loads happen at the same time and that the writeback of s1 to state1 is overlapped with the return, i.e. free.

It seems like an obvious optimization to notice that s0 could be updated in parallel with the two initial s1 updates, i.e.

    s1 ^= s0;
    s1 ^= s0 >> 26;

can instead be written as

    s0 ^= s0 >> 26; // These two clock cycles can be overlapped with the previous s1 updates!
    s1 ^= s0;

since we don't care about the s0 value after this point and XOR operations are commutative (it is of course possible that the compiler is smart enough to do the same optimization, but I doubt it):

This is two clock cycles faster than the original code.

Terje

Comment Rubylith was state of the art! (Score 3, Interesting) 60

My father spent months at his home-made light table back around 1965 cutting traces in rubylith film in order to create the offset masks for orienteering maps.

He needed one such mask for each color in the finished map, any mistakes had to be fixed with small amounts of red lacquer which then had to dry completely before it could be recut.

The big advantage for VLSI vs a map was that most lines were straight so you didn't need to trace curved lines like you do for the contours on a map.

Terje

Comment Re:And where does "velocity" come from? (Score 1) 131

Sorry, that's simply wrong:

The basic output (usually once per second for most GPS chipsets) consists of 7 parameters:

X,Y,Z and dX,dY,dZ along with T, wth the x,y,z values in an Earth Centered Earth Fixed coordinate system. I.e. velocity is an intrinsic output of the processing, resulting from the need to determine doppler values for all visible sats in order to track them.

Past this point many GPS units will do lots of post-processing, for some of them this includes using a lowpass filtered velocity model that uses position deltas instead of or in addition to the raw velocity outputs.

I have run over 500 orienteering races with various GPS units (mostly Garmin watches), and it is indeed true that tracking under a canopy (particularly when it is wet) can be a big challenge, but since the SirfSTAR chipset took over from Garmin's old 12-channel receiver, it is now perfectly usable.

http://tmsw.no/qr/index.php?us...

Regarding the original article: Distance measurements depend a lot on how the GPS filters individual measurements!

If you are running along a standard road, then your actual path will be pretty much identical to a set of straight lines, simply because the usual curves on a road are so wide that you get many GPS updates along them. The same goes for XC skiing where a GPS can easily overestimate the distance by introducing spurious sideways noise.

My wife's iPhone consistently overestimate the length of the XC ski tracks in Rauland, Telemark (Norway) due to this: Since I have mapped this entire area I can measure the exact lengths directly from the aerial photos and they corresponds much better with my Garmin 620 and 410 watches. My Garmin Montana which has a much better antenna will normally provide significantly better tracking.

Terje

Comment Log tables for the win! (Score 1) 220

I had both the school issued smallish slide rule and one I had inherited from my father which was much nicer.

However, I used log tables when I wanted even more accurate answers: One year my main wish on my Christmas list was a book that provided full 5-digit log tables. :-)

After I read about Taylor series I realized that I could calculate anything to any accuracy I wanted, but it still took a couple of hours (high school physics class) to calculate pi by hand with 20+ digits using the arctan formula.

(At this point in time, ~1975, I had just bought my first calculator, a TI SR50A which still works when I connect it to a couple of AA batteries instead of the original NiCd rechargable.)

Terje

Comment This is a SF story, sort of (Score 2) 130

Last night I bought a Baen EBook: Terry Bisson - Numbers Don't Lie.

The book consists of three stories, one of them is about a "Hole in the Hole", a Brooklyn junkyard which uses a spacetime rift connecting the junkyard to the Moon in order to get rid of old tires. Our protagonists tries to use said rift to retrieve one of the three Apollo Moon buggies that were left behind.

Terje

Comment The US wants Instant Gratification (Score 4, Interesting) 439

Having lived in the US previously, I much prefer the Norwegian (and most of the EU) model where you go online or to a dealer and figure out exactly which car you want:

Engine, paint, transmission, seats etc, then you haggle a bit about the price and order it, with delivery a number of weeks later.

In the US it seemed dealers really needed to be able to deliver a car TODAY, not tomorrow or next week.

Personally I ordered a Tesla 4WD model a few days ago, for delivery in the beginning of March.

The main difference from my last car was in the fixed sticker price: No haggling about rebates, just a simple take it or leave it offer.

The main reason for getting a Tesla here in Norway is of course our incredibly high import duties and taxes on regular cars (a car with a V8 engine would probably cost 2.5 to 3 times as much as in the US), while a Tesla has no import duties, no sales tax, no road fees and lots of free parking & charging. In a couple of years they have stated that the relative subsidies for zero emission vehicles will get a cap, so only smaller cars will be able to take full advantage.

Terje

Comment Re:work to live (Score 1) 55

I live in Norway where we definitely work to live, not the opposite, but I did spend one year in the US back in 1991-92.

During that year I know that I worked the least number of hours of any of the engineers in my department, averaging 45 hours/week, but I still got a couple of bonuses which they really didn't need to give me, since they knew that I was going back to Oslo after 12 months.

Here in Norway we have 5 weeks of vacation time every year, and employers get in big trouble if they have any employees who don't take all of that. (You can push a maximum of two weeks in front of you from one year to the next.)

OTOH my wife would gladly confirm that I spend a lot of hours in front of my PC every day, but I consider that to be some of my hobbies, not work. :-)

I.e. stuff like NTP Hackers, Mill Computing, Lidar-based mapping work etc.

Terje

Comment What about the interconnect? (Score 1) 150

In pretty much every HPC cluster I've seen or been personally involved with (mostly oil/seismic processing or crash simulations), the type of CPU is only one of the cost drivers!

Typically you end up spending about as much on fast interconnects as you do on motherboards/cpus/ram etc. The main exception to this rule is when you have an embarrassingly parallelizable workload, with small memory footprint and no need for cross-system communication, i.e. like a Monte Carlo simulation or password cracking.

For oil we used the largest single-image NUMA/SMP machine we could get at the time, this machine did the initial gridding of the problem space, then a standard cluster of 1K dual-cpu motherboards (i.e. 2K cpus) took over and did the main part of the actual processing.

There are exceptions though, like if you are doing Linear Programming type optimization which can be really hard to parallelize, or if you are using very expensive SW:

When you pay more for the SW than for the HW it is running on, then it makes sense to use bleeding-edge (gamer type) cpus.

Terje

Comment Rather a very poor job. :-( (Score 1) 100

I have made many, many panoramas, but none in the multi-gigapixel range, so I realize that they had a very tough stitching job, but even so: This was a pretty bad job!

All the central snow fields look like the result of randomly placed images: With a motorized pano head they should have been able to locate each image pretty accurately even before they started the SIFT runs to look for matching key points (which can be hard in a blue sky or on white snow).

More problematic is the fact that they must have done the actual stitching pretty much without proper blending from one image to the next:

Within the first minute of zooming around in the image I stumbled across a perfectly straight line with totally different exposure/lighting on each side, giving an almost black/white boundary that screams "This isn't natural!".

The proper way to blend such images is to use a multi-spectral approach: Low frequency information (like average light level) is blended across the entire overlap, while higher frequencies use narrower and narrower bands. Doing it this way means that even if one image had a clear blue sky and the next was taken when the sun was hidden by a cloud, the overlap is nearly perfect.

Terje

Comment Nash just got the Abel price! (Score 5, Informative) 176

Just 5 days ago, John F. Nash and Louis Nirenberg got the Abel price in a ceremony in Oslo:

http://www.abelprize.no/

With a diploma handed over by the Norwegian King Harald and a NOK 6M prize this is the closest thing math has to a Nobel prize.

Unlike the Fields Medal there is no age limit, so just like the Nobel prizes it tends to be given out at a later date, for work that has proven itself to be really outstanding.

Terje

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