Study without a direct object is just "okumak" "ders çalışmak" vs. I just want a direct object with this meaning, you must say "study for" (I am studying for the test). If you just use a direct object, it means "çok dikkatli araştırmak/bakmak " (I studied the painting). :)
Quite the opposite, actually :-)
Quoting from Tips and Notes:
ki can attach onto the ends of some pronouns to show possession. These are equivalent to words like mine in English.
Regardless, we are not using the "Possessive ki" in this sentence, but rather the "Relative Clause ki". I understand the confusion because this can sometimes be translated into English possessive structure:
yarınki sunum = the presentation that is tomorrow = tomorrow's presentation