This paper is to study the tracking control of a piezoceramic actuator (PA). Due to the inherent hysteresis nonlinearity, the PA always causes position error in the open-loop system and instability in the closed-loop system. To remedy this problem, a new control method combining the feedforward and feedback controllers is proposed to improve the dynamic performance of the PA. In the feedforward...

Pseudo-Relevance Feedback (PRF) is a widely used technique which aims to improve the query representation assuming as relevant the top ranked documents. This should results in better performance as, after the expansion and re-weigh of the original query, the resultant vector should contain all those worth features able to express utterly the user’s information need. This paper presents the appl...

Nonminimum Phase Discrete Time Models Yuping Gu and Masayoshi Tomizuka Department of Mechanical Engineering University of California at Berkeley, Berkeley, CA 94720-1740 [email protected] [email protected] Abstract This paper is concerned with performance enhancement of tracking control systems by multi-rate control. The feedback controller is updated at the same rate as the sampling r...

In this paper we introduce our experiences of blended learning for open and distance learning in our university in recent years. We form our basic philosophies to implementing blended learning and make one blended learning system with 10 subsystems, which is consisted of online learning environment, instruction design, interaction, space, time, curriculum, learning material, community of practi...

This paper describes Peking University’s approaches to the Ad Hoc, Data Centric and Relevance Feedback track. In Ad Hoc track, results for four tasks were submitted, EÆciency, Restricted Focused, Relevance In Context and Restricted Relevance In Context. To evaluate the relevance between documents and a given query, multiple strategies, such as Two-Step retrieval, MAXLCA query results, BM25, dis...

This thesis falls in the field of embedded real-time systems, and more precisely the in-vehicle embedded software for the evaluation of the next generation of driving assistance systems (ADAS). This document presents the three principal axes of the thesis: First, the development of a dynamic reconfigurable middleware called SCOOT-R. Second, the development of distributed real-time scheduling st...

The present study investigates empirical models of groupwork management in online collaborative learning environments, based on the data from 298 students (86 groups) in United States. Data revealed that, at the group level, groupwork management was positively associated with feedback and help seeking. Data further revealed that, at the individual level, groupwork management was positively asso...

To cope with delay during an online download session, web service providers often present feedback cues to keep downloaders informed of progress. Yet, empirical work examining the downloaders’ perception of delay or their attitudes toward the feedback provided is scant. Moreover, only few studies have addressed the two variables in conjunction with downloaders’ demographics. This study intends ...