Posts by Oleg Zaikin

1) Message boards : News : Results of SAT-CMS (Message 1409) Posted 27 Sep 2020 by Oleg Zaikin Post: As a result of the SAT-CMS experiment, 29 pairs of orthogonal diagonal Latin squares (ODLS) of order 10 were found. 2 cell mapping schemas (CMS) were used for this purpose. 18 found pairs are based on the first CMS, the remaining 11 pairs are based on the second one. CMS is in fact a relation between 2 Latin square from an orthogonal pair: for each element of the first square it shows where this element should be placed in the second square. Therefore, one can effectively construct the second square from a pair given the first square. The computing application was based on the CDCL algorithm aimed at solving the Boolean satisfiability problem (SAT). For each studied CMS, we first reduced a problem of finding pairs of ODLS of order 10 (that match the CMS) to SAT. Then, the obtained SAT problem was splitted into subproblems which in turn formed workunits. Finally, from found satisfying assignments (solutions of the SAT problems) we constructed the corresponding pairs of ODLS. All the found pairs are listed here. We are very grateful to all the crunchers who took part in the experiment!
2) Message boards : Number crunching : Project is out of work (Message 1366) Posted 27 Aug 2020 by Oleg Zaikin Post: The project has been selected as the Formula BOINC sprint project for 08/27/2020 22:00 (UTC) to 08/30/2020 21:59 (UTC). This tends to bring a lot of attention and extra participants to a project. However, the project is currently out of work. Is there a possibility of creating more work both for those who have been working on this project regularly, as well as those who will be joining the project new for the sprint race? We were not aware of the sprint, sorry about that. Unfortunately, all workunits of the current experiment have already been generated, so we have nothing to generate at the moment. It would be better to choose another project for this purpose.
3) Message boards : News : First workunits of new search will be generated soon (Message 1352) Posted 11 Aug 2020 by Oleg Zaikin Post: So, what is the plan for this project? Michael. For example, is someone working on releasing an ARM linux version? Jon Unfortunately, no. The computing application is based on a SAT, so it is a quite complex application. That is why we made versions only for Windows and Linux.
4) Message boards : News : First workunits of new search will be generated soon (Message 1351) Posted 11 Aug 2020 by Oleg Zaikin Post: So, what is the plan for this project? Michael. We launched a small experiment aimed at finding pairs of orthogonal diagonal Latin squares (ODLS) of order 10 based on a given cell mapping schema (CMS). Using such a CMS, one can construct the second square from a pair given the first square. Finally, four CMS will be processed in the experiment. The computing application is based on a SAT solver. For each workunit where a pair of ODLS is found, a badge will be given. By now, in 23 workunits pairs of ODLS were found and we are working on the corresponding badge.