University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Computer science & Population. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Palmprint Recognition Based on Complete Direction Representation

Abstract: Direction information serves as one of the most important features for palmprint recognition In the past decade, many effective direction representation (DR)-based methods have been proposed and achieved promising recognition performance However, due to an incomplete understanding for DR, these methods only extract DR in one direction level and one scale Hence, they did not fully utilize all potentials of DR In addition, most researchers only focused on the DR extraction in spatial coding domain, and rarely considered the methods in frequency domain In this paper, we propose a general framework for DR-based method named complete DR (CDR), which reveals DR by a comprehensive and complete way Different from traditional methods, CDR emphasizes the use of direction information with strategies of multi-scale, multi-direction level, multi-region, as well as feature selection or learning This way, CDR subsumes previous methods as special cases Moreover, thanks to its new insight, CDR can guide the design of new DR-based methods toward better performance Motived this way, we propose a novel palmprint recognition algorithm in frequency domain First, we extract CDR using multi-scale modified finite radon transformation Then, an effective correlation filter, namely, band-limited phase-only correlation, is explored for pattern matching To remove feature redundancy, the sequential forward selection method is used to select a small number of CDR images Finally, the matching scores obtained from different selected features are integrated using score-level-fusion Experiments demonstrate that our method can achieve better recognition accuracy than the other state-of-the-art methods More importantly, it has fast matching speed, making it quite suitable for the large-scale identification applications

Adaptive Fuzzy Tracking Control of Nonlinear Time-Delay Systems With Dead-Zone Output Mechanism Based on a Novel Smooth Model

Abstract: This paper presents a novel fuzzy adaptive controller for controlling a class of dead-zone output nonlinear systems with time delays. A new approximate model is first designed to describe a special dead-zone phenomenon encountered by the output mechanism of nonlinear systems, and the proposed smooth model can be conveniently fused with available adaptive fuzzy control techniques. In addition, the coupling effect that the dead-zone output and the time-delayed states coexist in a common coupling function makes the tracking control design more complicated. To further address this difficulty, a compensation method using mean-value theorem with Lyapunov–Krasovskii function is presented in this paper. By using the proposed output dead-zone model, and based on Lyapunov synthesis, a new optimized algorithm is developed to guarantee the prescribed convergence of tracking error and the boundedness of all the signals in the closed-loop systems. Simulations have been implemented to verify the performance of the proposed fuzzy adaptive controller.

Adaptive CUSUM procedures with EWMA-based shift estimators

Abstract: Adaptive Cumulative SUM charts (ACUSUM) have been recently proposed for providing an overall good detection over a range of mean shift sizes. The basic idea of the ACUSUM chart is to first adaptively update the reference value based on an Exponentially Weighted Moving Average (EWMA) estimate and then to assign a weight on it using a certain type of weighting function. A linear weighting function is proposed that is motivated by likelihood ratio testing concepts and that achieves superior detection performance. Moreover, in view of the lower efficiency in tracking relative large mean shifts of the EWMA estimate, a generalized EWMA estimate is proposed as an alternative. A comparison of run length performance of the proposed ACUSUM scheme and other control charts is shown to be favorable to the former.

Concentrated control, institutions, and banking sector: An international study

Abstract: Using a broad sample of listed commercial banks in East Asia and Western Europe, this paper investigates the relations among concentrated control, a set of bank operating characteristics, and legal and regulatory regimes We find that banks with concentrated control exhibit poorer performance, lower cost efficiency, greater return volatility, and higher insolvency risk, relative to widely held ones We also document that legal institutions and private monitoring effectively reduce the detrimental effects of concentrated control and that official disciplinary power plays a weak governance role, whereas government intervention exacerbates the adverse effects Further evidence shows that the relations between control concentration and bank operating characteristics are curvilinear and vary according to the types of controlling owners Overall, our findings support the contention that country-level institutions play important roles in constraining insider expropriation, and that private monitoring mechanisms are more effective than are public rules and supervision in governing banks