Write-Once Memory codes

Write-Once Memory codes or WOM codes have been introduced by Rivest&Shamir in 1982.
These pages bundle the results of my quest in this area. The following is provided:

• The report "A heuristic approach to find short efficient WOM codes"
• A list of short 2-write binary WOM codes
• A list of short multiple-write binary WOM codes
• The sample program "WOM_finder" as used to find 2-write binary WOM codes with arbitrary decoding map
• Two sample programs demonstrating the practical use of "best effort codes" to obtain high effective coding rates in classical WOM and cyclical storage applications

For any questions or suggestions, you can contact the author on bert.o.dobbelaere[at]telenet[dot]be

History

2017-07-21 Extended 2-write codes (known write number)
2017-06-19 Improved some 2-write codes (unknown write number)
2017-06-05 Add <1000>²/14 code and a few slightly improved 2-write codes.
2017-06-05 Improved "best effort" code for 16 symbols in 16 bit to an average of 11.028 writes.
2017-05-13 Add laminar <29,26>/7 code
2017-05-09 Add high sum rate multi-write codes with known write number for lengths up to 8 bit
2017-04-24 Add newly found <2⁹>³ / 16 code to multi-write tables (known write number ; R=1.6875) + demo program
2017-04-19 Minor update of report to v1.1 (extra codes + editorials), add "security video" example for "best effort" codes
2017-04-18 Add newly found <2⁸>⁴ / 18 code (R=1.7778)
2017-04-17 Add "best effort" code example
2017-04-15 Add newly found <2⁴>⁷ /15 code (R=1.8667)
2017-04-14 First upload