在時脈偏移裝置辨識技術的領域，Oka和楊祐齊等人提出了基於霍氏轉換的時脈偏移測量方法，可以有效避免低於主群體離群值的影響。此方法在短時間或是有高延遲抖動的情況下，時脈偏移測量值的穩定度皆優於蒐集最小偏移量或是線性規劃等既有方法。
本論文進一步提出一個改良的方法，能辨別資料是否為雙峰分布，接著使用Ostu法把資料分為兩個群體，然後各自完成剩餘的三階段測量，最後再給予權重計算時脈偏移。在資料為雙峰分布的情況，因為分出兩個群體進行計算，能避免區間大小開得過大，取得較佳的時脈偏移值。
比較楊的方法和本篇提出的方法，在雙峰分布且兩群體個數接近的情況下，實驗結果顯示本研究的方法可測得較穩定的結果。而當兩群體個數差距較大時，則與楊的方法有同等表現。在計算時間方面，雙峰分布下5000個偏移量的所需時間本研究平均比楊的方法多13.7%，非雙峰分布下5000個偏移量平均比楊的方法多7.1%。

Precise measurement is one of the essential requirement in the field of clock skew measurement. Yu-Chi Yang and Oka recently developed an improved Hough transform-based clock skew measurement method. This method is able to reach a ppm level precision estimation of clock skew with only few minutes of measurement, and it is robust in communications with lower outliers, which happens when the delay jitters are large. This research extends Yang’s method to address the case of offsets in bimodal distribution. In this research, we use Ostu’s algorithm to separate the offsets into two groups, then execute the rest of three steps process. Finally, we give the weight to compute the skew. This preprocessing prevents the region height from excessive increasing.
We compared our method with Yang’s method. The results of experiments show that the proposed method is able to provide more stable estimation in bimodal distribution when the number of primary peak is close to that of the second peak. In general, the proposed method spends 13.7% more than Yang’s method.

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