하영우. 2018. 수의적 /w/ 탈락의 양상과 해석. Studies in Phonetics, Phonology and Morphology 24.1. 69-91. 

The purpose of this paper is to investigate the relationship between aspects of optional /w/ deletion and language internal and external variables through quantified data in The Korean Corpus of Spontaneous Speech. The results are as follows: word initial position has no influence on /w/ deletion. This is because of the influence of words that have the characteristics of non-word initial position at the utterance dimension, even though they are considered to be in initial position in words of parts of speech such as auxiliary verbs. The /w/ deletion is influenced by syllable structure, and the occurrence is more frequent in CGV(C) structure than in GV(C). If it is under the same syllable structure, when [+labial] consonants and rounded vowels are preceded, /w/ deletion occurs more. However, deletion still occurs quite frequently when [-labial] consonants such as alveolars are preceded as well. To comprehensively explain these various types of /w/ deletion, the phonological constraints and reduction for the glide shall be introduced. (KAIST)