Nanyang Technological University

About: Nanyang Technological University is a education organization based out in Singapore, Singapore. It is known for research contribution in the topics: Computer science & Catalysis. The organization has 48003 authors who have published 112815 publications receiving 3294199 citations. The organization is also known as: NTU & Universiti Teknologi Nanyang.

Face recognition by support vector machines

Abstract: Support vector machines (SVM) have been recently proposed as a new technique for pattern recognition. SVM with a binary tree recognition strategy are used to tackle the face recognition problem. We illustrate the potential of SVM on the Cambridge ORL face database, which consists of 400 images of 40 individuals, containing quite a high degree of variability in expression, pose, and facial details. We also present the recognition experiment on a larger face database of 1079 images of 137 individuals. We compare the SVM-based recognition with the standard eigenface approach using the nearest center classification (NCC) criterion.

Reliable robust flight tracking control: an LMI approach

Abstract: This paper studies the reliable robust tracking controller design problem against actuator faults and control surface impairment for aircraft. First, models of actuator faults and control surface impairment are presented. Then a reliable robust tracking controller design method is developed. This method is based on the mixed linear quadratic (LQ)//H/sub /spl infin// tracking performance index and multiobjective optimization in terms of linear matrix inequalities. Flight control examples are given, and both linear and nonlinear simulations are given.

The Effect of SOX Internal Control Deficiencies on Firm Risk and Cost of Equity

Abstract: The Sarbanes-Oxley Act (SOX) mandates management evaluation and independent audits of internal control effectiveness. The mandate is costly to firms but may yield benefits through lower information risk that translates into lower cost of equity. We use unaudited pre–SOX 404 disclosures and SOX 404 audit opinions to assess how changes in internal control quality affect firm risk and cost of equity. After controlling for other risk factors, we find that firms with internal control deficiencies have significantly higher idiosyncratic risk, systematic risk, and cost of equity. Our change analyses document that auditor-confirmed changes in internal control effectiveness (including remediation of previously disclosed internal control deficiencies) are followed by significant changes in the cost of equity that range from 50 to 150 basis points. Overall, our cross-sectional and intertemporal change test results are consistent with internal control reports affecting investors' risk assessments and firms' cost of equity.

Effects of environmental aging on the mechanical properties of bamboo–glass fiber reinforced polymer matrix hybrid composites

Abstract: Short bamboo fiber reinforced polypropylene composites (BFRP) and short bamboo–glass fiber reinforced polypropylene hybrid composites (BGRP) were fabricated using a compression molding method. Maleic anhydride polypropylene (MAPP) was used as a compatibilizer to improve the adhesion between the reinforcements and the matrix material. By incorporating up to 20% (by mass) glass fiber, the tensile and flexural modulus of BGRP were increased by 12.5 and 10%, respectively; and the tensile and flexural strength were increased by 7 and 25%, respectively, compared to those of BFRP. Sorption behavior and effects of environmental aging on tensile properties of both BFRP and BGRP systems were studied by immersing samples in water for up to 1200 h at 25°C. Compared to BFRP, a 4% drop in saturated moisture level is seen in BGRP. After aging in water for 1200 h, reduction in tensile strength and modulus for BGRP is nearly two times less than that of BFRP. Use of MAPP as coupling agent in the polypropylene matrix results in decreased saturated moisture absorption level and enhanced mechanical properties for both BFRP and BGRP systems. Thus it is shown that the durability of bamboo fiber reinforced polypropylene can be enhanced by hybridization with small amount of glass fibers.

Rational designs and engineering of hollow micro-/nanostructures as sulfur hosts for advanced lithium–sulfur batteries

Abstract: Lithium–sulfur (Li–S) batteries have attracted much attention in the field of electrochemical energy storage and conversion. As a vital part of the cathode electrode, the host materials of sulfur usually have a strong impact on the capacity, energy density, cycle life and Coulombic efficiency of Li–S batteries. With their unique physical and chemical properties, the rationally designed hollow nanostructures show conspicuous advantages as sulfur hosts, and have significantly improved the overall performance of Li–S cells. The scope of this review considers the unique structural advantages of hollow host materials for high-performance Li–S batteries, together with a summary of recent advances in the design and synthesis of various hollow micro-/nanostructures with controlled shapes, tailored shell structures and designed chemical compositions. Finally, we propose some emerging requirements of sulfur hosts which we hope will shed some light on the future development trend of hollow structures for advanced Li–S batteries.