Before deciding if you are a resident for tax purposes you need to consider other factors. e.g. Are you intended to stay in Australia in long term? Have you had family in Aus? Did you keep a family home in Aus while you are away? Have you had significant investment in Aus? All these have to be taken into account.
If you are a resident for only part of the year. Technically you are only entitled to a portion of the tax free threshold.