A new tracking system for magneto-optical disk drives. Part II: Analysis and servo system

To reduce the average accessing time of a magneto-optical (MO) disk drive, which is a severe drawback of current products, a newly developed moving-magnet type tracking actuator has been designed and tested. The effort of developing a fast positioning actuator is divided into two parts. One is to develope a new driving mechanism having a fast tracking capability and the other is to adopt an advanced control scheme. In this work, the second effort is mainly addressed using a hybrid control and adaptive model-following control.     

FEATURE-BASED KOREAN GRAMMAR UTILIZING LEARNED CONSTRAINT RULES

In this paper, we propose a feature-based Korean grammar utilizing the learned constraint rules in order to improve parsing efficiency. The proposed grammar consists of feature structures, feature operations, and constraint rules; and it has the following characteristics. First, a feature structure includes several features to express useful linguistic information for Korean parsing. Second, a feature operation generating a new feature structure is restricted to the binary-branching form which can deal with Korean properties such as variable word order and constituent ellipsis. Third, constraint rules improve efficiency by preventing feature operations from generating spurious feature structures. Moreover, these rules are learned from a Korean treebank by a decision tree learning algorithm. The experimental results show that the feature-based Korean grammar can reduce the number of candidates by a third of candidates at most and it runs 1.5 ∼ 2 times faster than a CFG on a statistical parser.     

The integration of complete replanning and rule-based repairing for optimal operation of utility plants

The integration methodology of complete replanning and plan repairing is proposed to handle the prediction errors for energy demands during multiperiod operational planning. Complete replanning is implemented periodically and plan repairing is triggered during the execution interval. The plan repairing is constructed by a rule-based system because of real-time limitations. The efficiency index of a utility pump is introduced to determine startup/shutdown of equipment without integer programming in plan repairing. Case studies show that the proposed method is more profitable than the conventional replanning method. The total operating costs are reduced by 0.3-9.0% compared with the conventional replanning method.     

Plant-wide optimal byproduct gas distribution and holder level control in the iron and steel making process

A new plant-wide multiperiod optimization approach is proposed for optimal byproduct gas distribution to prevent unfavorable byproduct gas emission and equipment trip and simultaneously to maximize the efficiency of energy resource usage in the iron and steel making process. Compared with the previous approach, the proposed approach finds the optimal trade off among conflicting objectives such as holder level control, minimization of oil consumption and number of burner switching, and the maximization of generating electricity. To consider the different fuel load change operation according to the fuel types, both integer and continuous variables are used. Case studies were performed to verify the usefulness of the proposed approach, and the results show good performance in terms of the reduced number of burner switching which leads to the reduction of total cost and producing operation-easy solutions.