Performance monitoring of MPC based on dynamic principal component analysis

A unified framework based on the dynamic principal component analysis (PCA) is proposed for performance monitoring of constrained multi-variable model predictive control (MPC) systems. In the proposed performance monitoring framework, the dynamic PCA based performance benchmark is adopted for performance assessment, while performance diagnosis is carried out using a unified weighted dynamic PCA similarity measure. Simulation results obtained from the case study of the Shell process demonstrate that the use of the dynamic PCA performance benchmark can detect the performance deterioration more quickly compared with the traditional PCA method, and the proposed unified weighted dynamic PCA similarity measure can correctly locate the root cause for poor performance of MPC controller

Online Synchronous Language Learning: SLMS over the Internet

Learning a second language at a distance poses a tremendous challenge to learners. Physical distance from teachers and peers coupled with possible isolation from the relevant language community makes language learning extremely difficult. However, live interaction supported by synchronous learning management systems (SLMS) over the Internet holds great potential to address various difficulties facing distance language learners. By allowing students and instructors to negotiate linguistic issues together in real-time virtual settings, the interactive functions of such systems—online chat, whiteboards, and videoconferencing technology—can help foster vital learning communities in second language instruction. The study in this article offers an illustration that may contribute to further research and innovation in the use of SLMS to support language instruction in distance learning environments. This article will first discuss the needs of distance language learners and the importance of online synchronous interaction in distance-based language learning. It will then proceed to discuss the capabilities of an advanced SLMS over the Internet and to report the initial results from a pilot study involving learners' evaluation of this SLMS. The implications of these findings for future research will then be explored. The Needs of Distance Language Learners Along with its many advantages, including flexibility and low costs, traditional distance education often has disadvantages—such as a lack of communication, a sense of disconnectedness, and a lack of confidence commonly felt by learners. Distance language learners face even greater difficulties. Despite their wish to improve their proficiency in a given language, distance language learners find little opportunity to communicate in the language itself within this particular learning environment, and these same learners become very frustrated when they cannot converse spontaneously in face-to-face situations. This proble