1. One way to get different sequence of random numbers is not to use any seed at all, this will make the random number generator to use the current time as the seed.

    The Java documentation says:

    public Random()

    Creates a new random number generator. Its seed is initialized to a value based on the current time:

    public Random() this(System.currentTimeMillis());

    Two Random objects created within the same millisecond will have the same sequence of random numbers.

  2. Use the current system clock time to initialize the seed, the clock time will not be same.
  3. Use a global random number and use this to initialize all the random number generators.

Source: Weka FAQ