Comparison of green roof performance in stormwater mitigation

Paper no. 81365The impervious surfaces in urban areas often increase overland flow and river discharge leading to flooding issues. Green roof, being one low impact development technique, can potentially facilitate stormwater management and advert flooding problems. Although there are a number of studies examining the hydrologic behaviour of green roof, they are often limited to the monitoring periods which may not involve extreme rainfall events. They are also specific to the rainfall conditions of the study areas, making it difficult to transfer the knowledge to other countries. This study uses numerical models to quantify the hydrological behaviour of green roof and to examine the effectiveness of green roof in stormwater management. In particularly, it compares its performance in extreme rainfall events of different countries. A one-dimensional variably-saturated flow model is used. The calibrated model is subjected to the rainfall conditions of a few cities (i.e., Hong Kong, Singapore, Nagoya and London) of two-year return period. The reduction and the delay of the peak discharge, and the fraction of water retained are compared. The green roof performances (e.g., peak reduction, rainfall retained) vary due to the differences in rainfall characteristics (e.g., temporal pattern, total rainfall volume). The modeling results from different countries allow a consistent comparison, generating insights that might facilitate the transfer of results across countries. Overall, this study improves our understanding of hydrological behaviour of green roofs for stormwater management, in particularly benefiting the interpretation of green roof hydrological studies performed at rainfall conditions different from the area of interests.published_or_final_versio

Legal determinants of external finance revisited : the inverse relationship between investor protection and societal well-being

This paper investigates relationships between corporate governance traditions and quality of life as measured by a number of widely reported indicators. It provides an empirical analysis of indicators of societal health in developed economies using a classification based on legal traditions. Arguably the most widely cited work in the corporate governance literature has been the collection of papers by La Porta et al. which has shown, inter alia, statistically significant relationships between legal traditions and various proxies for investor protection. We show statistically significant relationships between legal traditions and various proxies for societal health. Our comparative evidence suggests that the interests of investors may not be congruent with the interests of wider society, and that the criteria for judging the effectiveness of approaches to corporate governance should not be restricted to financial metrics

Information diffusion in the U.S. real estate investment trust market

This study examines the information diffusion process in the U.S. Real Estate Investment Trust (REIT) market with a focus on the impacts of changing market environments, information supply, and information demand on the lead-lag effect. The results suggest that a significant lead-lag relationship exists between the lagged returns of big REITs and the current returns of small REITs. This relationship has slightly decreased along with policy and environment changes that occurred in the U.S. REIT market during the study period from 1986 to 2012, while still remaining significant in the most recent REIT market. The process of information diffusion is becoming unstable in recent years and the reverse lead-lag effect from small REITs to big REITs is observed especially when REIT market liquidity and return volatility are high. The lead-lag effect among REITs is driven largely by slow adjustment to negative information, which is magnified by a lack of information supply, especially as demand for such information increases. Finally, information flow from REITs with more media coverage to those with less media coverage becomes even more sluggish than the information flow from big REITs to small REITs

Economic policy uncertainty, short-term reversals, and investor sentiment

202307 bcwwNot applicableRGCPublished12 month

Gambling in the Hong Kong Stock Market

2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaAccepted ManuscriptOthersHong Kong Polytechnic UniversityPublishe

Momentum, reversals, and investor clientele

202210 bcchRGCPublished24 month

Intra-industry momentum: the case of REITs

Real estate investment trusts (REITs) provide a good setting to examine intra-industry momentum. The industry is relatively homogenous and well defined, and the industry experienced structural changes that allow us to test alternative explanations for the observed momentum effect. Specifically, we test predictions that are related to investor overconfidence (based on Daniel, Hirshleifer, and Subrahmanyam (1998)) and the speed of information diffusion (based on Hong and Stein (1999)). The first predicts a stronger momentum effect in REITs during the post-1990 period than during the pre-1990 period due to more valuation uncertainty in the post-1990 period. The second predicts a more pronounced momentum effect in REITs during the pre- 1990 period than during the post- 1990 period due to the higher speed of information diffusion in the post-1990 period. Our findings tend to support the first prediction. Specifically, while we do not find a momentum effect in REITs during the pre- 1990 period, we find a strong and prevalent momentum effect in REITs during the post-1990 period. (C) 2003 Elsevier Science B.V. All rights reserved

National culture and the cost of debt

2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaAccepted ManuscriptOthersHK Polytechnic UniversityPublishe

The cross section of expected REIT returns

In this study, we examine the cross-sectional determinants of expected REIT returns. We examine both the pre- and post-1990 periods, since the structure of the REIT market changed substantially around 1990. The determinants of expected returns differ between the two subperiods. In the pre-1990 subperiod, momentum, size, turnover and analyst coverage predict REIT returns. In the post-1990 period, momentum is the dominant predictor of REIT returns. Given the strength of the momentum effect in the post-1990 period, we examine it in great detail. For the whole period, and for the post-1990 period where the momentum profit is strongest, our evidence is generally consistent with the studies on common stocks, other than REITs. The only striking exception is that we find that momentum is stronger for the larger REITs rather than for the smaller REITs. In our multiple regressions that include the characteristics as well as interactions between past returns and firm characteristics, the turnover-momentum interaction effect provides the most significant results. More specifically, momentum effects are stronger for more liquid REITs

Expression of aquaporin-4 in thymus and thymoma of myasthenia gravis patients: a pilot study

Oral PresentationIntroduction: Neuromyelitis optica (NMO) is a serious central nervous system disorder characterised by monophasic or recurrent optic neuritis and acute transverse myelitis. 60 to 70% of NMO patients have detectable serum anti-aquaporin-4 (AQP4) antibodies. An autoimmune pathogenesis of NMO is suggested by clinical association of NMO with other autoimmune diseases especially myasthenia gravis (MG). Thymic abnormalities (hyperplasia and thymoma) are common in MG. The role of the thymus and thymoma in the pathogenesis of NMO is unknown. We aimed to study the expression of AQP4 in thymus and thymoma of MG patients. Methods: Thymus and thymoma tissues were obtained from MG patients who underwent thymectomy as standardised treatment. AQP4 protein and mRNA in thymus and thymoma tissues were studied by western blot and reverse transcriptase PCR (RT-PCR). Positive control was human skeletal muscle (express AQP4); negative control was cultured human neuroblastoma cells (do not express AQP4). Results: Four MG patients were studied. Thymoma (two encapsulated, one invading surrounding tissues) from three MG patients (two females; mean age, 37.3 years; range, 22-50 years) express AQP4 detected on western blot; one of the three had RT-PCR performed and was positive for AQP4 mRNA. A single female patient aged 28 years had MG associated with thymic follicular hyperplasia, whose thymus lysate was negative for APQ4 on western blot. All four MG patients were seropositive for anti-acetylcholine receptor antibodies, and none was seropositive for anti-AQP4 antibodies. Conclusion: This pilot study revealed that thymomas of MG patients express AQP4 whereas hyperplastic thymus of MG patients does not express AQP4