The Chinese University of Hong Kong

About: The Chinese University of Hong Kong is a education organization based out in Hong Kong, China. It is known for research contribution in the topics: Population & Computer science. The organization has 43411 authors who have published 93672 publications receiving 3066651 citations.

Graphene-based photocatalytic composites

Abstract: The use of graphene to enhance the efficiency of photocatalysts has attracted much attention. This is because of the unique optical and electrical properties of the two-dimensional (2-D) material. This review is focused on the recent significant advances in the fabrication and applications of graphene-based hybrid photocatalysts. The synthetic strategies for the composite semiconductor photocatalysts are described. The applications of the new materials in the degradation of pollutants, photocatalytic hydrogen evolution and antibacterial systems are presented. The challenges and opportunities for the future development of graphene-based photocatalysts are also discussed.

Time-of-arrival based localization under NLOS conditions

Abstract: Three or more base stations (BS) making time-of-arrival measurements of a signal from a mobile station (MS) can locate the MS. However, when some of the measurements are from non-line-of-sight (NLOS) paths, the location errors can be very large. This paper proposes a residual test (RT) that can simultaneously determine the number of line-of-sight (LOS) BS and identify them. Then, localization can proceed with only those LOS BS. The RT works on the principle that when all measurements are LOS, the normalized residuals have a central Chi-Square distribution, versus a noncentral distribution when there is NLOS. The residuals are the squared differences between the estimates and the true position. Normalization by their variances gives a unity variance to the resultant random variables. In simulation studies, for the chosen geometry and NLOS and measurement noise errors, the RT can determine the correct number of LOS-BS over 90% of the time. For four or more BS, where there are at least three LOS-BS, the estimator has variances that are near the Cramer--Rao lower bound.

Does country matter

Abstract: Previous studies have explored the predictors of business unit performance in multiple-business firms and investigated the extent of the effect of industry, corporate, and business unit on the performance of a business unit. These studies have focused almost exclusively on examining performance differences within a single country, thus treating country effects as external to business unit performance. In contrast, this study focuses on multinational corporations and examines the extent to which country effects explain the variation in the performance of foreign affiliates. Our findings show that country effects are as strong as industry effects, following affiliate effects and corporate effects. Our results also suggest that corporate and affiliate effects tend to be more critical in explaining the variation in foreign affiliate performance in developed countries, whereas country and industry effects are more salient in developing countries. Copyright © 2004 John Wiley & Sons, Ltd.