Laser induced THz emission from femtosecond photocurrents in Co/ZnO/Pt and Co/Cu/Pt multilayers

The ultrashort laser excitation of Co/Pt magnetic heterostructures can effectively generate spin and charge currents at the interfaces between magnetic and nonmagnetic layers. The direction of these photocurrents can be controlled by the helicity of the circularly polarized laser light and an external magnetic field. Here, we employ THz time-domain spectroscopy to investigate further the role of interfaces in these photo-galvanic phenomena. In particular, the effects of either Cu or ZnO interlayers on the photocurrents in Co/X/Pt (X = Cu, ZnO) have been studied by varying the thickness of the interlayers up to 5 nm. The results are discussed in terms of spin-diffusion phenomena and interfacial spin-orbit torque.Comment: 15 pages, 6 figures, 2 table

Transformation of UML interaction diagrams into contract specifications for object-oriented testing

Testing is an important means to ensure the quality of software systems. Contract specification can be used to formally specify the cluster level of object-oriented software, which can then be tested using TACCLE, an advanced methodology for object-oriented testing. The use of formal specifications as a testing base has many advantages. However, such specifications are not easily understood and therefore not widely used in the software industry. On the other hand, UML, a semi-formal modeling language, is becoming increasingly popular and widely accepted. In particular, UML interaction diagrams specify the dynamic, interacting behavior among the objects of an object-oriented system. If the transformation of UML interaction diagrams into Contract specifications can be automated, the TACCLE methodology can be applied directly to test object-oriented software at the cluster level. In this paper, a method to transform UML interaction diagrams into Contract specifications is proposed based on the UML meta-model. A prototype has been developed. © 2007 IEEE.published_or_final_versio

Smoking among Hong Kong Chinese women: behavior, attitudes and experience

published_or_final_versio

Polynomial Growth Harmonic Functions on Finitely Generated Abelian Groups

In the present paper, we develop geometric analytic techniques on Cayley graphs of finitely generated abelian groups to study the polynomial growth harmonic functions. We develop a geometric analytic proof of the classical Heilbronn theorem and the recent Nayar theorem on polynomial growth harmonic functions on lattices \mathds{Z}^n that does not use a representation formula for harmonic functions. We also calculate the precise dimension of the space of polynomial growth harmonic functions on finitely generated abelian groups. While the Cayley graph not only depends on the abelian group, but also on the choice of a generating set, we find that this dimension depends only on the group itself.Comment: 15 pages, to appear in Ann. Global Anal. Geo

Helping cancer patients quit smoking by increasing their risk perception: A study protocol of a cluster randomized controlled trial

BACKGROUND: Despite smoking cessation can largely improve cancer prognosis and quality of life, many patients continued smoking after the diagnosis of cancer. This study aims to test the effectiveness of a smoking cessation intervention using risk communication approach to help cancer patients quit smoking, and to improve their health related quality of life. METHODS: A cluster randomized controlled trial will be employed. Cancer patients who continued smoking after the diagnosis of cancer and have medical follow-up at the out-patient clinics of the five acute hospitals in Hong Kong will be invited to participate. Subjects in the experimental group will receive (1) health warnings of smoking based on a special designed leaflet; and (2) a patient-centred counseling from nurse counselors with emphasis on risk perceptions of smoking to cancer prognosis. Additionally, they will receive two more telephone counseling at 1-week and 1-month. Control group receive standard care and a generic self-help smoking cessation booklet. Outcomes measure include (a) self-reported and the biochemically validated quit rate, (b) patient's smoking reduction by at least 50 % compared to baseline, (c) quit attempt(s), (d) change in the intention to quit, (e) change in risk perceptions of smoking, and (f) change in health related quality of life. DISCUSSION: This study will make an important contribution to evidence-based practice by testing the effectiveness of a tailored smoking cessation intervention for cancer patients. The results will support the development of clinical practice guidelines to promote smoking cessation in cancer patients to improve their prognosis and quality of life.published_or_final_versio

Effectiveness of a parental training programme in enhancing the parent-child relationship and reducing harsh parenting practices and parental stress in preparing children for their transition to primary school: a randomised controlled trial

published_or_final_versio

Two isoperimetric inequalities for the Sobolev constant

In this note we prove two isoperimetric inequalities for the sharp constant in the Sobolev embedding and its associated extremal function. The first such inequality is a variation on the classical Schwarz Lemma from complex analysis, similar to recent inequalities of Burckel, Marshall, Minda, Poggi-Corradini, and Ransford, while the second generalises an isoperimetric inequality for the first eigenfunction of the Laplacian due to Payne and Rayner.Comment: 11 page

"Quit to Win": a smoking cessation promotion and scientific research project with community participation

Poster Discussion 47. Benefits of Community Collaboration and Outreach: no. PD-1146-21Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: In Hong Kong, the daily smoking prevalence dropped to 10.7% in 2012. However, over 60% of the daily smokers had never tried and 53% had no intention to quit. Urgent actions and novel approaches are needed to promote smoking cessation. To actively offer smokers assistance to quit, the Hong Kong Council on Smoking and Health (COSH) partnered with Schools of Nursing and School of Public Health of The University of Hong Kong (HKU) to launch a smoking cessation contest – “Quit to Win” Contest in 2009, to raise public awareness on the harms of smoking and the benefits of quitting, and motivating smokers to quit. The contest was re-organized in 2010 and evolved to become “Quit to Win” Smoke-free …published_or_final_versio

An evaluation study of a gender-specific smoking cessation program to help Hong Kong Chinese women quit smoking

published_or_final_versio

A dynamic fault localization technique with noise reduction for java programs

Existing fault localization techniques combine various program features and similarity coefficients with the aim of precisely assessing the similarities among the dynamic spectra of these program features to predict the locations of faults. Many such techniques estimate the probability of a particular program feature causing the observed failures. They ignore the noise introduced by the other features on the same set of executions that may lead to the observed failures. In this paper, we propose both the use of chains of key basic blocks as program features and an innovative similarity coefficient that has noise reduction effect. We have implemented our proposal in a technique known as MKBC. We have empirically evaluated MKBC using three real-life medium-sized programs with real faults. The results show that MKBC outperforms Tarantula, Jaccard, SBI, and Ochiai significantly. © 2011 IEEE.published_or_final_versionThe 11th International Conference on Quality Software (QSIC 2011), Madrid, Spain, 13-14 July 2011. In International Conference on Quality Software Proceedings, 2011, p. 11-2