Версія даної теми для друку

Автор: nikelong Mar 21 2012, 23:18

SubsetSum@Home

http://volunteer.cs.und.edu/subset_sum/

http://volunteer.cs.und.edu/subset_sum/team_display.php?teamid=9 - Ukraine

About SubsetSum@Home

The Subset Sum problem is described as follows: given a set of positive integers S and a target sum t, is there a subset of S whose sum is t? It is one of the well-know, so-called ”hard” problems in computing. It's actually a very simple problem, and the computer program to solve it is not extremely complicated. What's hard about it is the running time – all known exact algorithms have running time that is proportional to an exponential function of the number of elements in the set (for worst-case instances of the problem).

Over the years, a large number of combinatorial problems have been shown to be in the same class as Subset Sum (called NP-complete problems). But, depending on how you measure the size of the problem instance, there is evidence that Subset Sum is actually an easier problem that most of the others in its class. The goal of this project is to strengthen the evidence that Subset Sum is an easier hard problem.

Suppose we have a set of n positive whole numbers S whose maximum number is m. We will define the ratio n/m to be the density of the set and denote the sum of all elements in the set as ∑S. If you look at the list of sums produced by subsets of S, you notice that very few sums are missing if S is dense enough. In fact, it appears that there is an exact density threshold beyond which no sums between m and half the sum of S will be missing. Our preliminary experiments have led to the following hypothesis: A set of positive integers with maximum element m and size n > floor(m/2)+1 has a subset whose sum is t for every t in the range m < t < ∑S − m.

So here's where you can help. So far, we haven't been able to prove the hypothesis above. If you want to be really helpful, you can send us a proof (or show us where to find one in the research literature), and the project will be done. But if you want to be slightly less helpful and have more fun, you can volunteer your computer as a worker to see how far we can extend the empirical evidence. You will also be helping us figure out better ways to apply distributed computing to combinatorial problems.

SubsetSum@Home is based at the Computer Science Department of the University of North Dakota.

Научные результаты и публикации, связанные с проектом SubsetSum@Home:
http://people.cs.und.edu/~tdesell/papers/2015_cwit_sssathome.pdf

Автор: Rilian Apr 23 2012, 10:42

Есть задания (под мак и линукс)

Автор: Rilian Apr 24 2012, 11:44

есть задания под все системы!

Автор: Rilian Apr 30 2012, 12:42

SubsetSum@Home: Added more workunits

2012-04-30: Let me know if you're getting the 0.05 application (and if they're validating correctly). I just grabbed some of the new workunits, and it took the 0.05 applicaton, so I hope it's working for everyone, but if not let me know.

Автор: Rilian May 5 2012, 10:50

SubsetSum@Home: Updated applications and credit

2012-05-05: Credit should be fixed at 60 per workunit now while we're still in the alpha stages. I've updated the applications to 0.08 which should really fix the validation issue -- the error was pretty stupid on my part, and I was totally looking in the wrong area of the code. It wasn't parsing the command line arguments correctly (I was using atoi when I should have been using atol, and those variables were uint32_t instead of uint64_t. So I'm really hoping everything should be validating smoothly now, and that the credit should be a bit more fair for a project in this stage. So let me know how everything is crunching, and if you're still having any validation issues. If everything is working, then I'll start on getting the CUDA applications out to everyone (which should be at least 10x faster than the CPU version), and get the assimilator crunching away.

Автор: Arbalet Apr 12 2015, 19:37

Команда проекта SubsetSum@Home представила первую статью о проблеме суммы подмножеств на 14-м Канадском семинаре по теории информации (CWIT 2015).
Статья открыта для прочтения по данному линку: http://people.cs.und.edu/~tdesell/papers/2015_cwit_sssathome.pdf
Благодарят за поддержку и предоставленные вычислительные мощности!

Автор: Arbalet Apr 21 2015, 21:23

Главразраб проекта http://volunteer.cs.und.edu/csg/forum_thread.php?id=2020 партию новых рабочих заданий. Также призывает дезигнеров-участников присылать свои варианты бейджиков для SubsetSum@Home.

Автор: astronom2003 Nov 27 2015, 10:28

Ещё один мёртвый проект. Страница проекта не открывается. На boincstats находится в "Retired Projects". Перенесите в "Завершені проекти".

Автор: Death Dec 3 2015, 21:55

http://csgrid.org/csg/subset_sum/ да ладно

команда номер 3

http://csgrid.org/csg/team_display.php?teamid=3

Автор: astronom2003 Dec 4 2015, 00:56

Да, вроде живой...
Просто в первом посте топика ссылки совсем другие

и они не работают.
Death,я не модератор и заменить их не могу...
На boincstats этот проект в завершённых проектах и статистика по нему не ведётся :

"Детальная статистика
SubsetSum@Home
Этот проект больше не активен. Статистика 'заморожена' на день последнего обновления."

http://boincstats.com/ru/stats/132/project/detail
http://boincstats.com/ru/stats/132/country/list/
http://boincstats.com/ru/stats/132/user/list/0/0/Ukraine - там везде всё по нулям.


Учитывая то, что из 13 учасников команды считает (и то очень условно - у него "В среднем за день" - 50.41) аж 1 человек, а проект даже не в статистике boincstats, то может нафиг такой проект?

Автор: Death Dec 4 2015, 04:09

http://stats.free-dc.org/stats.php?page=proj&proj=sub

[wildlife,climate,dna,subset_sum] update!

Just wanted to give everyone an update as things have been a bit quiet on my front. I moved into a new house over the last week or so, which has limited my time quite a bit (and my internet connection for awhile). We're almost all moved in now, so there should be a more movement from me this week. We have some new DNA@Home runs that we will be getting started - and I think I might have found/fixed a potential bug that was causing some of the errors in the DNA@Home workunits.

Travis Desell on Wednesday, December 2nd
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