1. An apparatus for detecting sentence boundaries, comprising: a sentence boundary candidate extracting unit extracting a sentence boundary candidate from an input document; a document context analyzing unit extracting features from information on preceding and following contexts of the sentence boundary candidate, the features being used in two or more statistical algorithms; a sentence boundary candidate classifying unit classifying whether the sentence boundary candidate is a sentence boundary or not, using the features and the two or more statistical algorithms; and a sentence generating unit extracting sentence units from the document based on a result of the classification of whether the sentence boundary candidate is a sentence boundary or not, wherein the document context analyzing unit comprises: a punctuation mark feature extractor extracting information on whether the sentence boundary candidate is a punctuation mark; a blank feature extractor extracting information on whether a following syllable of the sentence boundary candidate is a blank; a syllable feature extractor extracting information on first to n-th preceding syllables of the sentence boundary candidate and information on first to n-th following syllables of the sentence boundary candidate; a token feature extractor extracting information on first to n-th preceding tokens of the sentence boundary candidate and information on first to n-th following tokens of the sentence boundary candidate; and a quotation mark feature extractor extracting information on a number of quotation marks existing between a beginning of a target sentence and the sentence boundary candidate.