<i>FERMI</i> -LAT DETECTION OF PULSED GAMMA-RAYS ABOVE 50 GeV FROM THE VELA PULSAR

Leung, Gene C. K.,Takata, J.,Ng, C. W.,Kong, A. K. H.,Tam, P. H. T.,Hui, C. Y.,Cheng, K. S. IOP Publishing 2014 ASTROPHYSICAL JOURNAL LETTERS - Vol.797 No.2

<P>The first Fermi-Large Area Telescope (LAT) catalog of sources above 10 GeV reported evidence of pulsed emission above 25 GeV from 12 pulsars, including the Vela pulsar, which showed evidence of pulsation at > 37 GeV energy bands. Using 62 months of Fermi-LAT data, we analyzed the gamma-ray emission from the Vela pulsar and searched for pulsed emission above 50 GeV. Having confirmed the significance of the pulsation in 30-50 GeV with the H test (p-value similar to 10(-77)), we extracted its pulse profile using the Bayesian block algorithm and compared it with the distribution of the five observed photons above 50 GeV using the likelihood ratio test. Pulsation was significantly detected for photons above 50 GeV with a p-value of = 3 x 10(-5) (4.2 sigma). The detection of pulsation is significant above 4 sigma at > 79 GeV and above 3 sigma at > 90 GeV energy bands, making this the highest energy pulsation significantly detected by the LAT. We explore the non-stationary outer gap scenario of the very high-energy emissions from the Vela pulsar.</P>

Implementing the smart city: who has a say? Some insights from Hong Kong

Kevin Y. K. Leung,H. Y. Lee 서울시립대학교 도시과학연구원 2023 도시과학국제저널 Vol.27 No.-

Over the years, the concept of the ‘smart city’ has become increasingly popular, and planning institutions seem to be more than keen to incorporate buzzwords associated with the smart city into their strategic city-wide plans, like IoT (Internet of Things) or AI (artificial intelligence), to name a few. Beyond these buzzwords, however, it seems that researchers and policymakers have mainly focused on the policies and characteristics of a smart city with only limited consideration for whether the planning stages have involved its citizens, or whether its citizens are even in support of these measures. Particularly in East Asia, consultative approaches seem to provide only tokenistic opportunities at best for citizens to have a say about their vision of ‘smart’ futures. Hence, this paper presents an extensive analysis on the history of implementing strategic city-wide plans by planning institutions, elaborating on how the concept of the ‘smart city’ gradually expanded into popular usage, using the case of Hong Kong. Studying Hong Kong’s urban planning strategies reveals the complexities of policy implementation in a city with an escalating sense of fear and mistrust between the people and the government, and where some of its citizens are wary of further integration with mainland China, charting the many incompatibilities of what it means to be ‘smart’ between the government and citizens. Whether the citizens’ needs are met are evaluated along a modified hierarchy of needs inspired by Maslow ([1954]. Motivation and Personality. New York, NY: Harper), and recommendations are provided that identify the many opportunities and challenges that lie ahead for cities of the future to truly become smart.

Clinical effectiveness of mindfulness-based music therapy on improving emotional regulation in blind older women: A randomized controlled trial

Sunny H.W. Chan,Meryl Y.C. Cheung,Armstrong T.S. Chiu,Mimi H.T. Leung,Michael C.C. Kuo,Donald Y.C. Yip,Carole C.Y. Hui,Sally W.I. Kam,King Yeung,Doreen S.P. Mui,Shu-Mei Wang,Calvin C.K. Yip 한국한의학연구원 2023 Integrative Medicine Research Vol.12 No.4

Background: This study aimed to investigate clinical effectiveness of a structured eight-week mindfulness-based music therapy (MBMT) program on improving mood regulation in older women with blindness. This investigation compared a MBMT group with a mindfulness intervention (MI) group and a control group. Methods: Ninety-two older females with blindness from a residential setting in Hong Kong were recruited and randomly allocated to a MBMT (n = 31), MI (n = 30), or control (n = 31) group. Psychological measurements regarding mood regulation and general mood states (namely, Difficulties in Emotion Regulation Scale [DERS], Geriatric Depression Scale [GDS], and Depression Anxiety Stress Scales-21), were taken at pretest and posttest. Outcome assessors were blinded to group assignment. Results: Data was analyzed based on intention-to-treat basis. At posttest, DERS scores in the MBMT group (mean differences and 95% confidence interval: 12.1, 5.5 to 18.8) and the MI group (7.2, 0.5 to 13.8) were lower than that in the control group. GDS scores in the MBMT group (2.9, 1.7 to 4.0) and the MI group (1.7, 0.6 to 2.9) were lower than those in the control group. Compared with the MI group, the MBMT group improved emotional awareness sub-scores in DERS (2.1, 0.2 to 4.1) and appeared to lower depression in GDS scores (1.1, -0.0 to 2.3; p = 0.053). Conclusion: MBMT seems more beneficial than MI alone for improving emotional regulation in older women with blindness. The combination of mindfulness and music can generate a synergetic effect by enhancing both attention and appraisal components within the emotional-regulation process. Trial registration: ClinicalTrials.gov, NCT05583695.

Diffracted moire fringes as analysis and alignment tools for multilayer fabrication in soft lithography (3 pages)

Lee, J.-H.,Kim, C.-H.,Kim, Y.-S.,Ho, K.-M.,Constant, K.,Leung, W.,Oh, C.-H. AMERICAN INSTITUTE OF PHYSICS 2005 APPLIED PHYSICS LETTERS Vol.86 No.20

MULTIPLE STRATEGIES TO DEVELOP ALLERGEN-SPECIFIC IMMUNOTHERAPY FOR SHELLFISH ALLERGY

Ka Hou Chu,Nicki Y.H. Leung,Christine Y.Y. Wai,Patrick S.C. Leung 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Simulation of vibrations of Ting Kau Bridge due to vehicular loading from measurements

Au, F.T.K.,Lou, P.,Li, J.,Jiang, R.J.,Zhang, J.,Leung, C.C.Y.,Lee, P.K.K.,Lee, J.H.,Wong, K.Y.,Chan, H.Y. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast strengthened by transverse cables and struts. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the heavy traffic on the bridge, and threats from typhoons and earthquakes originated in areas nearby, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. Baseline finite element models of various levels of sophistication have been built not only to match the bridge geometry and cable forces specified on the as-constructed drawings but also to be calibrated using the vibration measurement data captured by the Wind and Structural Health Monitoring System. This paper further describes the analysis of axle loading data, as well as the generation of random axle loads and simulation of vibrations of the bridge using the finite element models. Various factors affecting the vehicular loading on the bridge will also be examined.

Predictors of Long-term Abstinence Among Chinese Smokers Following Treatment: The Role of Personality Traits

Leung, Doris Y.P.,Au, Doreen W.H.,Lam, Tai-Hing,Chan, Sophia S.C. Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Four hundred and thirty-five Chinese smokers who had attended the first smoking cessation clinic and received stage-matched individualized cessation counseling in Hong Kong during the period of August 2000 to January 2002 were successfully followed-up between February and August 2008. Some 38% of the participants (165/495) had stopped smoking during the 12-month follow-up after treatment. Participants with higher conscientiousness score (OR = 1.65, 95% CI: 1.09 - 2.48) and lower openness to experience score (OR = 0.64, 95% CI: 0.45 - 0.92) showed a greater likelihood of quitting smoking after controlling the effect of daily cigarettes smoked and stage of readiness at baseline. The study suggests an important role of conscientiousness and openness to experience on long-term quitting behaviors following treatment, and provides useful information for the development of matched intervention for smoking cessation among Chinese smokers.

아토피피부염의 병인기전 - 초항원과 알레르기 질환

조상현(S. H. Cho),(Donald Y. M. Leung) 대한천식알레르기학회 2001 천식 및 알레르기 Vol.21 No.6

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HIGH-ENERGY EMISSIONS FROM THE GAMMA-RAY BINARY LS 5039

Takata, J.,Leung, Gene C. K.,Tam, P. H. T.,Kong, A. K. H.,Hui, C. Y.,Cheng, K. S. IOP Publishing 2014 The Astrophysical journal Vol.790 No.1

<P>We study mechanisms of multi-wavelength emissions (X-ray, GeV, and TeV gamma-rays) from the gamma-ray binary LS 5039. This paper is composed of two parts. In the first part, we report on results of observational analysis using 4 yr data of the Fermi Large Area Telescope. Due to the improvement of instrumental response function and increase of the statistics, the observational uncertainties of the spectrum in the similar to 100-300 MeV bands and > 10 GeV bands are significantly improved. The present data analysis suggests that the 0.1-100 GeV emissions from LS 5039 contain three different components: (1) the first component contributes to <1 GeV emissions around superior conjunction, (2) the second component dominates in the 1-10 GeV energy bands, and (3) the third component is compatible with the lower-energy tail of the TeV emissions. In the second part, we develop an emission model to explain the properties of the phase-resolved emissions in multi-wavelength observations. Assuming that LS 5039 includes a pulsar, we argue that emissions from both the magnetospheric outer gap and the inverse-Compton scattering process of cold-relativistic pulsar wind contribute to the observed GeV emissions. We assume that the pulsar is wrapped by two kinds of termination shock: Shock-I due to the interaction between the pulsar wind and the stellar wind and Shock-II due to the effect of the orbital motion. We propose that the X-rays are produced by the synchrotron radiation at the Shock-I region and the TeV gamma-rays are produced by the inverse-Compton scattering process at the Shock-II region.</P>

Optimum LCVA for suppressing harmonic vibration of damped structures

Shum, K.M.,Xu, Y.L.,Leung, H.Y. Techno-Press 2017 Smart Structures and Systems, An International Jou Vol.20 No.4

Explicit design formulae of liquid column vibration absorber (LCVA) for suppressing harmonic vibration of structures with small inherent structural damping are developed in this study. The developed design formulae are also applicable to the design of a tuned mass damper (TMD) and a tuned liquid column damper (TLCD) for damped structures under harmonic force excitation. The optimum parameters of LCVA for suppressing harmonic vibration of undamped structures are first derived. Numerical searching of the optimum parameters of tuned vibration absorber system for suppressing harmonic vibration of damped structure is conducted. Explicit formulae for these optimum parameters are then obtained by a series of curve fitting techniques. The analytical result shows that the control performance of TLCD for reducing harmonic vibration of undamped structure is always better than that of non-uniform LCVA for same mass and length ratios. As for the effects of structural damping on the optimum parameters, it is found that the optimum tuning ratio decreases and the optimum damping ratio increases as the structural damping is increased. Furthermore, the optimum head loss coefficient is inversely proportional to the amplitude of excitation force and increases as the structural damping is increased. Numerical verification of the developed explicit design expressions is also conducted and the developed expressions are demonstrated to be reasonably accurate for design purposes.