• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.962-967
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• 2003

CFD data compression method based on supercompact multiwavelets is presented. High data compression can be achieved when taking advantage of the compact nature of multiwavelets. Thresholding technique is also a matter of primary concern in determining pressure ratio. In this paper, we apply thresholding for multiwavelets that considers the coefficient vector as a whole rather than thresholding individual elements. Various thresholding methods are described briefly. CFD data compression suggests that the multivariate thresholding method is suitable for supercompact multiwavelets.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1608-1615
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• 2004

CFD data compression methods based on Full-3D and Quasi-1D supercompact multiwavelets are presented. Supercompact wavelets method provide advantageous benefit that it allows higher order accurate representation with compact support. Therefore it avoids unnecessary interaction with remotely located data across singularities such as shock. Full-3D wavelets entails appropriate cross-derivative scaling function & wavelets, hence it can allow highly accurate multi-spatial data representation. Quasi-1D method adopt 1D multiresolution by alternating the directions rather than solving huge transformation matrix in Full-3D method. Hence efficient and relatively handy data processing can be conducted. Several numerical tests show swift data processing as well as high data compression ratio for CFD simulation data.

• Journal of Mechanical Science and Technology
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• 제17권11호
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• pp.1784-1792
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• 2003

A hybrid method with supercompact multiwavelets is suggested as an efficient and practical method to compress CFD dataset. Supercompact multiwavelets provide various advantages such as compact support and orthogonality in CFD data compression. The compactness is a crucial condition for approximated representation of CFD data to avoid unnecessary interaction between remotely spaced data across various singularities such as shock and vortices. But the supercompact multiwavelet method has to fit the CFD grid size to a product of integer and power of two, m${\times}$2$^n$. To resolve this problem, the hybrid method with combination of 3, 2 and 1 dimensional version of wavelets is studied. With the hybrid method, any arbitrary size can be handled without any shrinkage or expansion of the original problem. The presented method allows high data compression ratio for fluid simulation data. Several numerical tests substantiate large data compression ratios for flow field simulation successfully.

• 한국항공우주학회지
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• 제33권12호
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• pp.18-25
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• 2005

본 논문에서는 supercompact 다중 웨이블릿 기법과 이 기법의 유동 시뮬레이션 데이터에의 적용을 발표한다. Supercompact 웨이블릿 방법은 간결한 지원(support)을 제공할 수 있고 또 속성이 다른 떨어져 있는 데이터와(예: 충격파의 불연속구간 또는 와동을 가로지르는 부분) 불필요한 상호작용을 피할 수 있는 점에서 유동 시뮬레이션 데이터를 위한 적합한 웨이블릿 방법이라 할 수 있다. 데이터 압축을 위한 임계처리법(thresholding)은 다중 웨이블릿의 공분산 벡터 구조 기반 하에 적용된다. 본 논문은 3차원으로의 기법 확장이 설명 분석되었다. 수치실험은 본 방법이 여러 이론적인 이점을 제공할 수 있고 실제 결과에 있어서 큰 데이터 압축 비율을 산출 할 수 있음을 보여준다.