對於次序代基因重組，組裝工具以及其對應的參數選擇對於組裝的品質有很大的影響。在本篇研究中，三種組裝工具： Velvet, SOAPdenovo, ABySS被考慮為分支因子，對應於各工具所特有的參數被當作巢狀因子，以及各工具共有的參數被當作是共享因子。因為基因的組裝是通過電腦模擬重組的，這個選擇問題就成了電腦實驗上對於於上述參數的最優解問題

在這篇研究中，我們提出了一個二階段式的過程來處理這個最優解問題。 首先，我們應用分支拉丁設計探索反應曲面的大致情況，在第二階段，高斯過程模型被應用於建構反應曲面， 然後根據最大化期望函數準則選擇下一個實驗點直到停止的條件滿足為止。在模擬方面，這個二階段過程的表現相當不錯。同時，當應用在實際資料的時候，這個過程迅速的選擇了一個反應值比較大的區域，最終選擇到的實驗點的值也比其他的方法好。

For de novo assembly of next-generation sequencing data, the selection of assembly tool and the corresponding parameters have a great effect on the quality. The tool is treated as the branching factor. Three tools: Velvet, SOAPdenovo and ABySS are considered which are regarded as the levels of the
branching factor. And the parameters which are special for each tools are treated as nested factors. Besides, the parameters shared by all tools are regarded as shared factor. In this study, we want to choose the tool and corresponding parameters that optimize the quality under limited resource.

Because the de novo assembly is simulated with computer, the selection becomes the optimization problem of computer experiment with respect to the factors. We propose a sequential procedure to choose the assembly tool and the corresponding optimal parameters simultaneously. Firstly, we apply the Branching Latin hypercube design to explore the
response surface. Secondly, Gaussian Process model is applied to construct the response surface and select the next experiment point by maximizing the Expected Improvement function until the stopping criterion is meet. The performance of the numerical simulation seems well. The implementation of real data can search into the region with larger value of response quickly and access to a better
experiment point compared to other methods.

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