Palm-line detection

Author name used in this publication: David ZhangBiometrics Research Centre, Department of ComputingRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Detecting wide lines using isotropic nonlinear filtering

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Carbon emission right as a new property right: rescue CDM developers in China from 2012

Clean development mechanism (CDM) is encountering many uncertainties due to the coming end of the commitment period and critically suggested reformation. As the largest participant in the CDM market, China shoulders the biggest proportion of market risk. Among the studies on CDM in China, few have focused upon the legal aspect of CDM, which is crucial in defending developers’ interests. To fill this research gap in making the transition from policy to law, this paper claims that carbon emission right, which is the basis of trade, should be attributed as a property right in Property Law of People’s Republic of China. The present study will discuss the characteristics of carbon emission, definition, and legal attribution of carbon emission right. The valid object of carbon emission right in the CDM market under Property Law should be certified emissions reductions (CERs). The usufructuary right could be specifically applied in practice to the owners’ property right on CERs in China. Although experience from the CDM is not fully applicable to the development of cap and trading, the success of CDM market provides a reasonable platform to study emission right in the view of legal science. Furthermore, the proposed research acts as the pioneer study that lay the theoretical foundations in legal science on emission right trading for other potential schemes, which in turn addresses international environmental issues.published_or_final_versio

Fast block-based image restoration employing the improved best neighborhood matching approach

2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A tongue-print image database for recognition

Author name used in this publication: David ZhangBiometrics Research Centre, Department of ComputingVersion of RecordPublishe

Microstructural Characterization of Graphite Spheroids in Ductile Iron

The present work brings new insights by transmission electron microscopy allowing disregarding or supporting some of the models proposed for spheroidal growth of graphite in cast irons. Nodules consist of sectors made of graphite plates elongated along a hai direction and stack on each other with their c axis aligned with the radial direction. These plates are the elementary units for spheroidal growth and a calculation supports the idea that new units continuously nucleate at the ledge between sectors

A Bilayer Osteochondral Scaffold with Self‐Assembled Monomeric Collagen Type‐I, Type‐II, and Polymerized Chondroitin Sulfate Promotes Chondrogenic and Osteogenic Differentiation of Mesenchymal Stem Cells

Osteochondral (OC) injuries are suffered by over 40 million patients in Europe alone. Tissue-engineering approaches may provide a more promising alternative over current treatments by potentially eliminating the need for revision surgery and creating a long-term substitute. Herein, the goal is to capture the natural biological and mechanical properties of the joint by developing a bilayer scaffold that is novel in two ways: first, a biomimetic bottom-up approach is used to improve production precision and reduce immunogenicity; monomeric collagen type I and II are self-assembled to fibrils and then processed to 3D scaffolds. Second, to induce a tissue-specific response in mesenchymal stem cells (MSCs), polymerized chondroitin sulfate (PCS) is synthesized and grafted to collagen II and hydroxyapatite (HA) is added to collagen I. Incorporation of PCS into collagen II induces a chondrogenic response by upregulation of COL2A1 and ACAN expression, and incorporation of HA into collagen I stimulates osteogenesis and upregulates the expression of COL1A2 and RUNX2. It is remarkable that MSCs give rise to distinct behavior of chondrogenesis and osteogenesis in the two different regions of the bilayer scaffold. This hybrid scaffold of collagen II-PCS and collagen I-HA offers a great potential treatment for OC injuries

Implications of large scale shifts in tropospheric NOx levels in the remote tropical Pacific

A major observation recorded during NASA's western Pacific Exploratory Mission (PEM-West B) was the large shift in tropical NO levels as a function of geographical location. High-altitude NO levels exceeding 100 pptv were observed during portions of tropical flights 5-8, while values almost never exceeded 20 pptv during tropical flights 9 and 10. The geographical regions encompassing these two flight groupings are here labeled "high" and "low" NOx regimes. A comparison of these two regimes, based on back trajectories and chemical tracers, suggests that air parcels in both were strongly influenced by deep convection. The low NOx regime appears to have been predominantly impacted by marine convection, whereas the high NOx regime shows evidence of having been more influenced by deep convection over a continental land mass. DMSP satellite observations point strongly toward lightning as the major source of NOx in the latter regime. Photochemical ozone formation in the high NOx regime exceeded that for low NOx by factors of 2 to 6, whereas O3 destruction in the low NOx regime exceeded that for high NOx by factors of up to 3. Taking the tropopause height to be 17 km, estimates of the net photochemical effect on the O3 column revealed that the high NOx regime led to a small net production. By contrast, the low NOx regime was shown to destroy O3 at the rate of 3.4% per day. One proposed mechanism for off-setting this projected large deficit would involve the transport of O3 rich midlatitude air into the tropics. Alternatively, it is suggested that O3 within the tropics may be overall near self-sustaining with respect to photochemical activity. This scenario would require that some tropical regions, unsampled at the time of PEM-B, display significant net column O3 production, leading to an overall balanced budget for the "greater" tropical Pacific basin. Details concerning the chemical nature of such regimes are discussed

Factors controlling tropospheric O3, OH, NOx, and SO2 over the tropical Pacific during PEM-Tropics B

Observations over the tropical Pacific during the Pacific Exploratory Mission (PEM)-Tropics B experiment (March-April 1999) are analyzed. Concentrations of CO and long-lived nonmethane hydrocarbons in the region are significantly enhanced due to transport of pollutants from northern industrial continents. This pollutant import also enhances moderately O3 concentrations but not NOx concentrations. It therefore tends to depress OH concentrations over the tropical Pacific. These effects contrast to the large enhancements of O3 and NOx concentrations and the moderate increase of OH concentrations due to biomass burning outflow during the PEM-Tropics A experiment (September-October 1996). Observed CH3I concentrations, as in PEM-Tropics A, indicate that convective mass outflux in the middle and upper troposphere is largely independent of altitude over the tropical Pacific. Constraining a one-dimensiohal model with CH3I observations yields a 10-day timescale for convective turnover of the free troposphere, a factor of 2 faster than during PEM-Tropics A. Model simulated HO2, CH2O, H2O2, and CH3OOH concentrations are generally in agreement with observations. However, simulated OH concentrations are lower (∼25%) than observations above 6 km. Whereas models tend to overestimate previous field measurements, simulated HNO3 concentrations during PEM-Tropics B are too low (a factor of 2-4 below 6 km) compared to observations. Budget analyses indicate that chemical production of O3 accounts for only 50% of chemical loss; significant transport of O3 into the region appears to take place within the tropics. Convective transport of CH3OOH enhances the production of HOx and O3 in the upper troposphere, but this effect is offset by HOx loss due to the scavenging of H2O2. Convective transport and scavenging of reactive nitrogen species imply a necessary source of 0.4-1 Tg yr-1 of NOx in the free troposphere (above 4 km) over the tropics. A large fraction of the source could be from marine lightning. Oxidation of DMS transported by convection from the boundary layer could explain the observed free tropospheric SO2 concentrations over the tropical Pacific. This source of DMS due to convection, however, would imply in the model free tropospheric concentrations much higher than observed. The model overestimate cannot be reconciled using recent kinetics measurements of the DMS-OH adduct reaction at low pressures and temperatures and may reflect enhanced OH oxidation of DMS during convection. Copyright 2001 by the American Geophysical Union

From regional pulse vaccination to global disease eradication: insights from a mathematical model of Poliomyelitis

Mass-vaccination campaigns are an important strategy in the global fight against poliomyelitis and measles. The large-scale logistics required for these mass immunisation campaigns magnifies the need for research into the effectiveness and optimal deployment of pulse vaccination. In order to better understand this control strategy, we propose a mathematical model accounting for the disease dynamics in connected regions, incorporating seasonality, environmental reservoirs and independent periodic pulse vaccination schedules in each region. The effective reproduction number, $R_e$, is defined and proved to be a global threshold for persistence of the disease. Analytical and numerical calculations show the importance of synchronising the pulse vaccinations in connected regions and the timing of the pulses with respect to the pathogen circulation seasonality. Our results indicate that it may be crucial for mass-vaccination programs, such as national immunisation days, to be synchronised across different regions. In addition, simulations show that a migration imbalance can increase $R_e$ and alter how pulse vaccination should be optimally distributed among the patches, similar to results found with constant-rate vaccination. Furthermore, contrary to the case of constant-rate vaccination, the fraction of environmental transmission affects the value of $R_e$ when pulse vaccination is present.Comment: Added section 6.1, made other revisions, changed titl