12:29 AM
I voted on every question, lol I still have votes to cast.
I lied. I just went through and I reached the limit :)
@gilles I'm still confused as to what I can ask, lol. I have a bunch of time complexity questions I could ask from recent quizzes and homeworks I was confused on. But again, I don't want them to be closed as being too simple...

@OghmaOsiris ask away (one, not a flood of similar questions)
The early beta is the right time to test what's acceptable and what isn't
there's no shame in having a question closed, on the contrary, you're doing your bit to shape the site
as long as you're reasonable and don't post a gardening question or something

but i wanted to know the time complexity of a recursive tomato harvest...

@OghmaOsiris 1 year per generation
maybe 6 months in some equatorial climates, but I don't think tomatoes can survive there

12:44 AM
i use a hydroponics bay

1:40 AM
1

In her 1987 seminal paper Dana Angluin presents a polynomial time algorithm for learning a DFA from membership queries and theory queries (counterexamples to a proposed DFA). She shows that if you are trying to learn a minimal DFA with $n$ states, and your largest countexample is of length $m$, ...

2:10 AM
0

Initially, Matroids were introduced to generalize the notions of linear independence of a collection of subsets $E$ over some ground set $I$. Certain problems that contain this structure permit greedy algorithms to find optimal solutions. The concept of Greedoids was later introduced to generaliz...

2:44 AM
man, science is hard. engineering has rotted my brain.
or maybe the problem is that it's almost 4am and I can't sleep
but seriously, the fine points of fixpoint definitions in CoIC/Coq are subtle

2:56 AM
I want to star this, but I don't think that would be good for the beta.
Hopefully we make it to open. We have more than machinelearning did.
Also, it's 4am, go to sleep. SE will still be here in the morning... err, later in the morning.

0

In a video discussing the merits of particle filters for localization, it was implied that there is some ambiguity about the complexity cost of particle filter implementations. Is this correct? Could someone explain this?

1 hour later…
4:28 AM
0

Sites in beta usually have a little 'site stats' box on the side so one can monitor the site health. How come this site doesn't have one ?

4:56 AM
0

In quantum computation, what is the equivalent model of a Turing machine? It is quite clear to me how quantum circuits can be constructed out of quantum gates, but how can we define a quantum Turing machine (QTM) that can actually benefit from quantum effects, namely, perform on high-dimensional...

1 hour later…
6:20 AM
0

Does SQL need subqueries? Imagine a sufficiently generalized implementation of the structured query language for relation databases. Since the structure of the canonical SQL SELECT statement is actually pretty important for this to make sense, I don't appeal directly to relational algebra, but ...

7:14 AM
Hello, everyone

3 hours later…
10:31 AM
0

We know that DFAs are equivalent to NFAs in expressiveness powers, there is also a known algorithm for converting NFAs to DFAs (unfortunately I do now know the inventor of that algorithm), which in worst case gives us $2^S$ states, if our NFA had $S$ states. My question is: what is determining t...

2 hours later…
12:23 PM
@OghmaOsiris: I'm a bit late to the party, but my suggestion would be to just try it out and see what happens. I did the same with my question about EPAL: I was testing how interested people are in very theoretical questions, and as it turns out I think that one was a bit too theoretical.

1 hour later…
1:47 PM
0

In an answer to this question I wrote the following LaTeX code: $$L=\{w\in\{0,1\}^*:|w|\geq n\text{ and the n-th symbol from the last one is 1}\}.$$ The output of this code should include four different curly brackets (two opening, two closing), but they are not being rendered. Inline LaTeX...

2 hours later…
4:05 PM
0

Suppose that a certain parallel application uses a master-slave design to process a large number of workloads. Each workload takes some number of cycles to complete; the number of cycles any given workload will take is given by a known random variable $X$. Assume that there are $n$ such workloads...

4:33 PM
0

According to Immerman, the complexity class associated with SQL queries is exactly the class of safe queries in $\mathsf{Q(FO(COUNT))}$ (first-order queries plus counting operator). Is there an extension of SQL (implemented and used in the industry) which captures polynomial time computable que...

4 hours later…
8:54 PM
@Gilles I did this the day before yesterday; can confirm that answering questions at 4am is suboptimal. :D
@AlextenBrink I like the question about EPAL. But as I don't see why the language can not be parsed by recursive descent I am apparently not suited to answer (or, in case I am right, your question is moot).

@AlextenBrink I don't think it's too theoretical, I could easily imagine worse :) No one knows an answer, that happens
Oh, you've passed the 500 rep bar too. Now we can ping @AlextenBrink @Raphael when we need a suggested edit approved
@Raphael I don't understand any better after having slept on it
Hopefully a Coq expert will come along at some point
I don't see how he can possibly get something that's not invariant wrt $u+C_2-C_1$
Ooh, the autorefresh of the front page's been deployed

9:13 PM
2

Today, a talk by Henning Kerstan ("Trace Semantics for Probabilistic Transition Systems") confronted me with category theory for the first time. He has built a theoretical framework for describing probablistic transition systems and their behaviour in a general way, i.e. with uncountably infinite...

Random Sudoku generator has been very heavily edited and reopened, y'all might want to take a second look

1 hour later…
10:21 PM
@Raphael Did you read my comment on the EPAL question regarding recursive descent? It does indeed look like it wasn't too theoretical after all, if I look at the number of upvotes.

10:49 PM
@Gilles I don't see any moderator tools, nor have I received any notifications about suggested edits so far. Am I missing something?

@Raphael mod tools is 1000 during private beta
notifications of suggested edits is 750
at 500, you can approve edits if we point them out to you

I see. We will see wether this happens, I will keep my eyes open.
Btw, good call regarding that Mortarboard badge. :>

Dammit, cs.stackexchange.com/q/110/98 is bugging me. Got to work on my masters thesis...
@Kevin Gilles said yesterday on Meta: "That said, if nobody gets the Suffrage badge today, we're doing it wrong."

@Raphael MB too

10:58 PM
Well, we have a VP and 2 MBs

congratulations to @Raphael and @AlextenBrink

@Gilles Do you pronounce your (nick)name like French, English or German would?

@Raphael since I'm French, I pronounce it like a Frenchman would, both in the logician and in the usual sense

Oh, no Suffrage badge for me so far. Looking up what it means...

@Raphael Suffrage = you cast 30 votes in a UTC day

11:00 PM
Thanks; feeld weird, actually. Have been an on-off user on several sites, but never this involved
oh, I thought I did this
@Gilles I see. Adapting brain-voice now. ;)

and still the site feels slow, French Language and Usage (which completely petered out after a few weeks) had >100 questions by that time
we have 35

More French speaking people than computer scientists around, I guess.

@Raphael no, not on SE

TGO had a lot more, but we've slowed down since.

(at the 2-day mark)

11:07 PM
@AlextenBrink Regarding your EPAL question: I read what you wrote, but the statement alone did little to convince my gut. Oh, wait... now I see. I had $a^nb^n$ in mind for some reason. Doh, my bad.
@AlextenBrink Regarding your heap automata answer: Not too sure about your use of $\cal{O}$ and $\omega$ there. What goes to infinity, as $n$ is fixed where you use them?
@Gilles Huh. I have been reluctant to invite people who did not sign up themselves (privacy). Once we hit public beta I will spread the word actively.
Maybe we should design flyers, posters, slides or something like that?
I am not too concerned about the number of questions. We have good ones, and knowledgeable members. I think quality will prevail and eventually attract quantity.

@Raphael it's too early for that, it's not a good idea to bring random people in before there's a minimum amount of content

Starting a site that is bound to be studies-related for many during lecture-free period (at least in Germany) might be bad timing, too.
@Gil
Arg. How can you trigger the name completion by keyboard?!
@Gilles You mean even when we hit public beta, we should not advertise the site?

@Raphael no, no, we should advertise, but not until we have a few hundred questions
wait a few weeks

The D-CON workshop is on these days here in Kaiserslautern. I was thinking wether I should say something there, but have decided to just annoy people with Stackexchange stories instead. ;)

Tell them to come to outdoors.SE

11:13 PM
talk to people one-on-one, but wait a bit until you make a poster

@Gilles Do you think the amount of questions is important for new members? I always figured that they were most likely to come so SE to ask a question, and might hit one or to recent questions. The backlog never seemed that important to me.

@Raphael depends who you're trying to recruit, true. It wouldn't be good to have a sudden influx of students asking homework questions before we have enough other content to balance them and enough manpower to answer them

Btw, both computerscience.se and computer-science.se are free, apparently... ;)
@Kevin nasty
@Gilles true

@Raphael ? Don't like the outdoors?

You shouldn't listen to me about site promotion, I'm not actually good at it
@Kevin or tell them to stay inside and read an SF book
in French

11:18 PM
@Gilles I have had succes with two strategies:
a) "You have a problem with X? No idea, maybe go to SE?" has worked wonders with tex.SE as they are magnificent at answering weird questions.
b) "Hey, look at this question. You know this stuff, right?" done that on math.SE, cstheory.SE
Type b) rarely sticks to the site as far as I can tell

I was firmly a b, but I might not be typical

@Gilles LOL. Chances are that many even speak French around here. Some even come from France, e.g. Bouajjani. Myself, I don't even speak a word French (besides "merci" and some I can't type)
I was told about then infant cstheory.SE by a very enthusiastic grad student who told me the site slowed down her dissertation. Moved around from there. And, obviously, you find Stackoverflow when googling for programming problems.
Oh, we have 23% unanswered questions. No good.

@Gilles Me too.
@Raphael Yeah, not good. Outdoors has always had a very high answer rate.

@Kevin I like the outdoors but get there not often enough. Never been to the site.
Well, we have some hard questions, too. I like that, actually; it also can be an incentive for people to join, if they perceive a need of their expertise.

@Kevin but that's a soft topic where anyone can venture an answer. Science is hard, if you don't know you can't fake it (much)
I've been trying to think up questions outside my area of expertise
such as the time synchronization question

11:29 PM
Me too.
Heading home, I'll try to think of more questions.

and I want to skew the site towards being for practitioners, this is the kind of stuff I'm interested in

Bye Kevin!
@Gilles I could swear I have heard somewhere about a protocol that converges towards synchronised clocks with few assumptions. Can't remember where, though.
I expect D-CON to prompt some questions for me as I am not really part of that community (concurrency theory). Won't be too practical, I'm afraid.
Have a nice exam question I have no nice and simple answer for, too. Gotta write it up over the weekend or on Monday.
It is hard for me to estimate what part of computer science is interesting for practitioners. Never been one, really.

@Raphael it's hard for me too… As a former scientist doing program analysis, I think all programmers should know more about this. As a programmer now, I see that we don't have time or social acceptance to adopt anything other than C (in my line of business).

@Raphael About the 23%, I don't think we should worry too much about it. For instance, I could answer my own EPAL question by summing up which algorithms can't parse EPAL, but that wouldn't be a very good answer I think.
@Raphael I've made a minor edit to my answer that hopefully clarifies things, but the answer is getting so big I'm starting to get a bit embarrassed by the number of edits I made... It is a brilliant question though.

11:46 PM
@Gilles Poor you. But then, you can talk to programmers and figure out how to attract them to CS if possible.
@AlextenBrink Just proposed an answer for the EPAL question. Hopefully I did not make a dumb mistake.

@Raphael That's the thing, I know they don't care

@AlextenBrink Yea, been there. It really is a great question. Nerd-sniped some guys today, too.
@Gilles :(
Not even if you break their toys>

@Raphael we do embedded stuff. Being the resident theorist I get to play with toys less and write more specs

The first talk today showed how the provably (and apparently standard) mutex algorithm by Dekker failed if implemented in C as it should be (using volatile on the important variables). Very intrigueing. C++ compiler can fix it, but in a dumb way. They do it a lot better.
@Gilles That sounds better

@Raphael the better compilers get, the less you can understand what little volatile means to them
@Raphael where is that?

11:50 PM
@Gilles Honestly, I have no idea about C and less about the wires. If I program, I use HPLs ;)
I don't know wether it is published yet, let me look.
Can' find it; will ask tomorrow. Read an abstract here, number 15
@AlextenBrink went silent. Now I'm scared. :D