為了瞭解生態環境的樣貌，傳統上對微生物的研究都是藉由實驗室的培養來進行，但是實驗室能培養的物種數量相當有限，大概只佔了大自然環境中的百分之一，為了近一步了解生態的多樣性，多源基因體學的研究開始蓬勃發展，透過多源基因體學研究，研究人員可以直接從生態環境中進行採樣與定序，然後藉由分類技術將序列資料進行重組以建立生態環境資料庫。在分類的過程中，由於序列資料本身有著多類別值的特性以及透過基因簽章所產生的高維度特徵問題，所以如何提升運算效率以及提升類別較多的階層的分類正確率是值得去探討的分類議題。本研究將結合階層式概念與特徵選取技術於此議題上，由於階層式架構建立出了每一階層各個類別其上、下階層的類別從屬關係，幫助排除了一些不必要的類別值，而特徵選取技術則是能將高維度特徵問題轉換成低維度特徵問題。本研究透過兩種方法的結合提出一種調整方法可以應用在基因序列的分類議題上，我們使用了兩個基因序列資料檔來做測試，測試結果發現，在分類正確率上，本研究方法和單純使用階層式架構下的方法相比，確實提升了各個階層的分類正確率，但是在和單純使用特徵選取的方法相比時，「科」、「屬」階層的分類正確率依然有些微差距；然而運算效率方面，本研究方法由於考量的類別值個數和特徵數量較少，因此和其他方法相比，本研究方法在分類時的運算速度是佔有非常大的優勢的。

In order to explore the microbes in an ecological environment, traditional studies for biologists are to culture them in laboratories. However, the microbes that can be cultured in laboratories are less than one percent of the whole microbes. Metagenomics is one of the popular topics in biology for studying microbes efficiently. Metagenomics is a technique for researchers to extract samples and sequences from ecological environments directly. Gene sequence data will be reorganized to create databases for ecological environments by classification techniques. Since the numbers of class values and features for gene sequence data are both large, it should be worthy to develop methods for improving the accuracy and computational efficiency in classifying gene sequence data. In this study, we combine taxonomy concept with feature selection technology for this purpose. Since taxonomy records the relations between the class values in different levels, it can be used to exclude unnecessary class values for class prediction. Feature selection technology can reduce the dimensionality of a data set. The experimental results on two gene sequence data sets show that our classification method outperforms the one with taxonomy in both prediction accuracy and computational efficiency. With respect to the method with feature selection, our method greatly improves the computational efficiency of the naïve Bayesian classifier, while the prediction accuracy of our method is slightly inferior in both family and genus levels.

蔡忠霖，(2010)。應用於多源基因體學分類問題之以熵值為基礎的特徵選取法。國立成功大學資訊管理研究所碩士班碩士論文。

盧鵬羽，(2011)。階層式概念應用於多類別基因序列資料分類之研究。國立成功大學資訊管理研究所碩士班碩士論文。

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