One of the most efficient nondestructive methods for pipeline in-line inspection is magnetic flux leakage inspection. Estimating the size of the defect from MFL signal is one of the key problems of MFL inspection. As the inspection signal is usually contaminated by noise, sizing the defect is an ill-posed inverse problem, especially when sizing the depth as a complex shape. An actor-critic structure-based algorithm is proposed in this paper for sizing complex depth profiles. By learning with more information from the (...) depth profile without knowing the corresponding MFL signal, the algorithm proposed saves computational costs and is robust. A pinning strategy is embedded in the reconstruction process, which highly reduces the dimension of action space. The pinning actor-critic structure helps to make the reward for critic network more efficient when reconstructing the depth profiles with high degrees of freedom. A nonlinear FEM model is used to test the effectiveness of algorithm proposed under 20 dB noise. The results show that the algorithm reconstructs the depth profile of defects with good accuracy and is robust against noise. (shrink)

王船山，名夫之，字而农，号姜斋，中岁自称“一瓠道人”。生于明朝万历四十七（1619）年，卒在清康熙三十一（1692）年。湖南衡阳人。王船山先生是中国历史上广博的学者和伟大的思想家。本书作者在详细查阅充 足的史料、充分躬身研究多年和多次船山遗迹考察的基础上，详述了船山的传奇一生及其心路历程。书中虽然主要是以船山的实际人生经历为表达目标，但同时也涉及了船山一些很精深的思想。通过对于船山及其思想的理解，我 们也可以进而了解人类的精神之伟大与崇高，了解古今中外的贤哲们，为了延续和发展人类的精神慧命所作的坚忍不拔的努力和贡献的意义。阅读此书，可以激发读者对于湖湘文化和传统文化的兴趣。.

This paper investigates the leaderless and leader-follower time-varying formation design and analysis problems for a group of networked agents subject to discontinuous communications. Firstly, a leaderless time-varying formation control protocol is proposed via the intermittent control strategy, where the control input of each agent is constructed by the distributed local state information and formation instructions in the communication time unit, but it is zero in the noncommunication time unit. Then, an explicit formulation of the formation center function is determined to (...) describe the formation movement trajectory of the whole networked agents. Leaderless time-varying formation design and analysis with discontinuous communications are given in the form of linear matrix inequalities. Moreover, the main results of the leaderless cases are extended to the leader-follower cases. Finally, two numerical examples are provided to illustrate the theoretical results of leaderless and leader-follower cases, respectively. (shrink)