Chronic Logic

Klei: That´s exactly what I suggested in my
Batch testing    thread :)
Should be easy to automate, maybe even with commandline support for the main program :)

Giving settling time in seconds wouldnt do the job, I guess. What we need is either a 'simulation time' display or an option like I suggested in the 'new ideas'-'batch testing' thread  (I didnt say 3/5 *seconds* there for exactly this reason :)

Once we have such, maybe there should be a way to store the settling time along with the bridge to make batch testing possible for bridges needing different delays. (or just specify a multiple test with delays 1,2,3,4,5,7,10,15,20 or such..  would take longer to test, though :)

Hmm.. did I misconfigure something, or is the contest bridge really meant to be tested with 7 cars?
Nice challenge if that's the case :-/

CL wrote: I apologize for the time it has taken to respond.  We decided to take a day off yesterday (I know, what were we thinking?).  

Hmm... you mean, you didnt work on Sunday? What a concept ;)

BTW: Contest rule 6 asks a password.
Do you mean the password I use for the forum or the password I got via mail at registration time?

Chillum: For me it is just the opposite:
I come up with a design, optimize it a bit and send it in.
Probably I have not the slightest chance to win now.
Seeing other numbers, I would have put in as much time as needed to reach and beat those - as long as others are in front of me, I can try to reach them. Not knowing where others are, I'll always think I am the greatest anyway and just take it easy ;)

Well, I see your point, CL. Dont take my postings harsh, too. This *is* the first contest and we all have to learn :)

I helped to organize contests and rules (sim racing, hot laps and races - online and offline) since more than 5 years now.

Here is what I think:

Your approach (not discussing numbers during the event) will lead to rather different designs and a wide spreaded score range (maybe shocking/frustrating people - just imagine a guy who send in a 220k bridge he is proud of finding out the winner did it with 20k [numbers are pure phantasy! 20k isnt enough to lay the deck now :) ])
It is a nice approach to get many different solutions.
I think, this community is strong enough not to cheat
(since you can put the no discussion part into the rules but there is no way to enforce it, no way to detect cheaters, ..) I had no problems with a similar thing years ago.

I would like to see a different type of contest here (not saying that all others are worse!):

More time (let's say a month), more than one entry per participant encouraged, newest one counts. Regular updates (daily if it can be automated) of the best solutions so far. Discussion encouraged, maybe even designs disclosed.
This emphasizes to find the best possible solution. People will push each other to lower and lower numbers. And the goal for the best shifts from winning the contest to the goal of staying ahead in the daily update (even if there is no prize for that one, I have seen this more than once - the human mind is twisted ;)

This ruleset has some advantages:
No problem with people whining about their discarded entries (they can always make a corrected submission).
Doesnt rely on rules no one can enforce.

Just put my bridge into their mailbox, at least I hope so ;)
As you never know whether an email arrives or not, some confirmation (automated reply) would be nice.

Now the waiting starts.. maybe thats the positive effect of not discussing numbers.. there is some tension now ;)

Hmm.. not post any numbers? Why do you think it discourages ppl? I think, everyone who is addicted like me is *encouraged* by having a certain goal.
To see what is possible always motivates me to reach at least the same :)

CL, by removing numbers that have been visible for a while to some lucky guys you have created an unfair advantage to these, IMHO. Now they know what is at least needed to win - but I (and most others) dont know these numbers :(

As you cannot prevent that people talk with each other, I'd say there is no point in censoring posts here.
Especially since the rules dont forbid such conversation.
Think about it..   and let us at least know whether
the numbers had 5 or 6 digits ;)

Thx all for the grats :)

Of course, I will make the bridge public, so we all can optimize it further. I really spend only a few hours to get the cables into place, so there should be at least some hundred bucks still to save :)

BTW: the design applies well to some other levels, e.g. normal level 12 can be done around 55k that way :)

OverClok: I looked at your designs and wonder what kind of dead end you run into?
Actually, first I thought, you want to make a joke and append my winning bridge to your rejected designs ;)

Your number 5 is basically what I had before I started to optimize..
Or did you use heavy steel for the supports?

Gray: It doesnt matter to me if they forgot to change my subtitle over implementing pretensioned cables :)

...actually just posting crap to check my current subtitle again :D

Yeah, triangle spamming age is over http://www.pontifex2.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

You can get my bridge at
ftp://ftp.complang.tuwien.ac.at/pub/herbert/maximus1.zip

I" target="_blank">ftp://ftp.complang.tuwien.ac.at/pub/herbert/maximus1.zip

I have included two other bridges, both do interesting collapses:

badtumbl is my first try, over optimized.
I had rectangular supports and tried to remove the lateral links at the bottom to save $. But this design seems to need the weight of these (There shouldnt be any other forces there.). Just re-insert another lateral link (to make it symmetric again) and it will work.

ok8not5 is even more interesting, as it can withstand 7 and 8 cars, but it collapses with 5 and 6. So if you ever wondered whether it is possible to build a bridge that gets more stable with more weight on it, look no further ;)
(on the other hand, it is probably the higher speed of the lighter train that brings down this bridge, not sure about this...)

Mendel wrote: AFAIK, Vienna has some nice bridges, too!

Yeah, with the not-so-small river Danube running through, we got some of these ;)

And we got some collapses, too!
Remember the ´Reichsbruecke´ going down early in the morning (with just an empty bus and a single car on it, iirc) the same day when Niki Lauda had his horrible Nurburgring fire crash?

And then there was the (unnamed) new bridge that collapsed even before it was opened to the public. Actually my father did the material calculation for that one! And he had a hard time to prove that his calculation was ok. Finally, he kept his job when they found out that more than one bridge worker redirected concrete transports to their own weekend house construction sites!
So the bridge went down. Well, we all know what happens if you remove just a small piece, or weaken a few links ;)

Mendel wrote: ´.. had 1 train passing just fine, but the back journey...´  
lol.. during optimization I got one that twisted over on the 4th pass http://www.pontifex2.com/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('>
Obviously, I experienced that twisting effect, too.
If you get my zip-file, you can see ´badtumbl´ collapsing exactly the way you describe.
But when I made the transition from rectangular supports to ´V´ supports, this effect completely vanished. I have never seen a V-support bridge twist over, so I wonder why OverClok had troubles with the V and went the other (wrong?) way towards rectangular supports..
And I still wonder where the asymmetric twist force come from.. Is it based on some inaccurate floating point calculations, where small truncation errors sum up over time, doesn´t the train run in the perfect centerline of the decks, or is it some random effects introduced on purpose?

.. why the simple links from Bridge Builder have been replaced with these structured links and complicated nodes in Pontifex. (I do *not* want to criticise this decision, I just want to understand it http://www.pontifex2.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

The structured links/nodes seem to have mostly disadvantages:
1. Shorter links are weaker now than longer ones due to compressed diagonal sublinks
2. The nodes are stiff and seem to break easily (in some situations they behave like ultra short (=ultra weak) links)
3. There are strange lateral forces induced to adjacent links when a node gets compressed (easy to see on top of cable carriers when you dont remove the lateral link between left and right carriers
4. the orthogonal arranged nodes look awkward in arches, and makes the arch really fragile now
5. I guess, it takes *much* more CPU time to calculate

Seeing all this (and I´m sure CL has been aware of this when changing the design), I wonder why it was changed.

2 guesses: CL wanted to have stiff nodes (better matches reality, but taking the first point into account I´d say it is worse now)
CL wanted to make better looking (not so simple) bridges (but taking the 4th point into account I´d say it is worse now)

Doh.. a 3rd guess: Did CL want to free us from the need to have supports going into the 3rd dimension to avoid the bridge falling to the side? But a simple X between symmetric links would have done the job, too (maybe generated automagically like the lateral link now)..

What do I miss here? What was the real ´design decision advantage´ of the structured approach?

(Edited by Calis at 1:47 am on Oct. 23, 2001)