U.S.-Mexico Cooperative Science: Nonlinear Optimization Techniques for Seismic Inversion Problems

9416004 Nocedal这个美洲项目奖将支持西北大学的Jorge Nocedal博士和墨西哥国立自治大学的Susana Gomez博士就地震反演问题的优化技术进行的合作研究项目。研究人员的目标是通过使用给定的地震数据集来确定地球的各种材料属性，如慢度和阻抗。地震反演需要解决两个优化问题：一个是高度非线性的中等规模的优化问题，另一个是接近二次型的非常大的优化问题。为解决这些优化问题，将开发一种新的优化方法，并在二维地震模型上进行测试。从地震地表数据确定地球的性质具有重要的现实意义。目前解决该问题的主要障碍是现有优化技术所需的计算时间过长。这项研究的目标之一是开发新的技术，以全自动的方式加快反演过程。目前的项目因合作者的专业知识互补而得到加强。Nocedal博士的主要研究集中在开发新的优化算法，能够快速解决非常大的问题，例如地震反演中出现的问题，而戈麦斯博士拥有开发解决全局和不可微优化问题的新方法的经验。***

9416004 Nocedal This Americas Program award will support a collaborative research project between Dr. Jorge Nocedal, Northwestern University, and Dr. Susana Gomez, Universidad Nacional Autonoma de Mexico, on optimization techniques for seismic inversion problems. The researchers aim to determine various material properties of the earth, such as slowness and impedance, by using given sets of seismic data. Seismic inversion requires the solution of two optimization problems: one highly non-linear and moderately large, and another nearly quadratic and very large. A new optimization method, tailored to solve these optimization problems, will be developed and tested on 2-dimensional seismic models. Determining the properties of the earth from seismic surface data is of great practical importance. The main obstacle to the solution of the problem at present is the excessive computing time required by current optimization techniques. One of the goals of this study is to develop new techniques that will speed up the inversion process in a fully automatic manner. The current project is enhanced by the complementarity of the collaborators' expertise. Dr. Nocedal's main research has focused on the development of new optimization algorithms capable of rapidly solving very large problems, such as those arising in seismic inversion, while Dr. Gomez has experience developing new methods for global and non-differentiable optimization problems. ***