CT理论与应用研究
CT理論與應用研究
CT이론여응용연구
COMPUTERIZED TOMOGRAPHY THEORY AND APPLICATIONS
2013年
4期
587-604
,共18页
分辨长度%分辨率矩阵%反演%模型评估
分辨長度%分辨率矩陣%反縯%模型評估
분변장도%분변솔구진%반연%모형평고
resolution length%resolution matrix%inverse problem%model appraisal
反演问题的时空间分辨率或称时空分辨长度是评估模型精细程度的重要参数,决定了该模型应用的范围和价值,但是分辨长度估算却是比反演更复杂和麻烦的数学问题。除了层析成像中广泛利用理论模型恢复试验定性提取空间分辨长度外,通过求解分辨率矩阵可定量获得分辨长度。通过矩阵操作给出的分辨率矩阵包括三类:直接分辨率矩阵、正则化分辨率矩阵和混合分辨率矩阵。这三类矩阵包含了反演本身不同侧面的信息,因此在一个反演应用中,同时提供这三类分辨率矩阵可更全面地评估反演模型分辨率分布。最近An(2012)提出了从大量随机理论模型及其解中统计出分辨率矩阵的方法。这种分辨率矩阵是从模拟真实反演实验的输入和输出模型中通过反演得到的,因此这种分辨率矩阵更能反映整个反演所涉及到的更多因素和过程;同时由于这种分辨率矩阵计算过程无需进行矩阵操作且不依赖于具体正演和反演方法,因此可以被应用于更普遍的反演问题。实际应用证明统计分辨率分析方法适用于对二维和三维层析成像反演模型进行分辨率分析。
反縯問題的時空間分辨率或稱時空分辨長度是評估模型精細程度的重要參數,決定瞭該模型應用的範圍和價值,但是分辨長度估算卻是比反縯更複雜和痳煩的數學問題。除瞭層析成像中廣汎利用理論模型恢複試驗定性提取空間分辨長度外,通過求解分辨率矩陣可定量穫得分辨長度。通過矩陣操作給齣的分辨率矩陣包括三類:直接分辨率矩陣、正則化分辨率矩陣和混閤分辨率矩陣。這三類矩陣包含瞭反縯本身不同側麵的信息,因此在一箇反縯應用中,同時提供這三類分辨率矩陣可更全麵地評估反縯模型分辨率分佈。最近An(2012)提齣瞭從大量隨機理論模型及其解中統計齣分辨率矩陣的方法。這種分辨率矩陣是從模擬真實反縯實驗的輸入和輸齣模型中通過反縯得到的,因此這種分辨率矩陣更能反映整箇反縯所涉及到的更多因素和過程;同時由于這種分辨率矩陣計算過程無需進行矩陣操作且不依賴于具體正縯和反縯方法,因此可以被應用于更普遍的反縯問題。實際應用證明統計分辨率分析方法適用于對二維和三維層析成像反縯模型進行分辨率分析。
반연문제적시공간분변솔혹칭시공분변장도시평고모형정세정도적중요삼수,결정료해모형응용적범위화개치,단시분변장도고산각시비반연경복잡화마번적수학문제。제료층석성상중엄범이용이론모형회복시험정성제취공간분변장도외,통과구해분변솔구진가정량획득분변장도。통과구진조작급출적분변솔구진포괄삼류:직접분변솔구진、정칙화분변솔구진화혼합분변솔구진。저삼류구진포함료반연본신불동측면적신식,인차재일개반연응용중,동시제공저삼류분변솔구진가경전면지평고반연모형분변솔분포。최근An(2012)제출료종대량수궤이론모형급기해중통계출분변솔구진적방법。저충분변솔구진시종모의진실반연실험적수입화수출모형중통과반연득도적,인차저충분변솔구진경능반영정개반연소섭급도적경다인소화과정;동시유우저충분변솔구진계산과정무수진행구진조작차불의뢰우구체정연화반연방법,인차가이피응용우경보편적반연문제。실제응용증명통계분변솔분석방법괄용우대이유화삼유층석성상반연모형진행분변솔분석。
The information of solution’s spatial resolution is important for model appraisal in an inversion, however, the computation to determine a spatial resolution is nontrivial and often more difficult than to solve an inverse problem. Visual inspection of the restoration of a synthetic structure widely applied in tomographic studies can give indicative information on spatial resolution distribution, however, resolution matrix estimation can give quantitative information of spatial resolution length for a general inverse problem. Resolution matrices obtained by matrix operation may be divided into three classes:direct resolution matrix, regularized resolution matrix and hybrid resolution matrix. Each matrix can give part of the information on the inversion, and then the simultaneous implementation of all three resolution matrices in a single study can potentially provide a complete understanding on the resolution length information. An (2012) proposed a new class of resolution matrices generated by a simple one-parameter nonlinear inversion performed based on limited pairs of random synthetic models and their inverse solutions. The estimates were directly retrieved from synthetic models and their inverse solutions, and then it can include the information on the whole inversion procedure;The independence on the degree of inverse skill used and the absence of a requirement for matrix operations indicated that this approach is particularly suitable for very large linear/linearized inverse problems. Inversion examples even for 3D inversion problem demonstrated that reasonable resolution lengths can be determined from statistic spatial resolution calculation.