Exchange-Rate Systems and Interest-Rate Behaviour: The Experience of Hong Kong and Singapore

The Currency Board System in Hong Kong and the monitoring band system in Singapore are important benchmarks for two different exchange-rate systems. In this paper we consider the implications of the two exchange-rate systems on the interest-rate behaviour of the two economies. We examine the domestic-US interest differentials under the two exchange-rate regimes during the Asian Financial Crisis as well as the pre- and post-crisis periods. Using a bivariate generalized autoregressive conditional heteroscedasticity model, we also investigate whether there is any change in the correlation between the domestic and US interest rates due to the Asian Financial Crisis.

Coexisting fast-scale and slow-scale instability in current-mode controlled DC/DC converters : analysis, simulation and experimental results

Author name used in this publication: Chi K. Tse2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Community-based Assessment for Memory and Motor Impairment Among Young Substance Abusers Using Standardised Instruments: A Hong Kong Experience

Abstract Sixty-three substance users aged between 12 and 25 were recruited into a community health evaluation programme. Use of ketamine, ecstasy and cocaine was prevalent. Neuropsychiatric symptoms were common. With the Rivermead Behavioural Memory Test, 79% of the clients were assessed to have impaired memory. Memory impairment was more pronounced among those using more types of drugs at high frequency, and having started drug use before the age of 15. The Bruininks-Oseretsky Test identified 72.4% of the clients with impairment in at least one of the three aspects defining motor proficiency − manual dexterity, fine-motor precision and fine-motor integration. Motor impairment could follow a period of substance use of less than one year. These findings revealed the high prevalence of memory and motor impairments among young substance users and the pressing need for prompt identification and intervention

The use of smart phones and their mobile applications among older adults in Hong Kong: An exploratory study

The purpose of this study was to explore social participation using smart phones by the older population in Hong Kong. The present study was conducted from 10-June-2013 to 16-August-2013. It was a cross-sectional survey study, and data were collected from street interviews. Potential participants were approached and invited to respond to a questionnaire. The locations for collecting data were evenly distributed on Hong Kong Island, Kowloon, and the New Territories. The size of the samples for Hong Kong Island, Kowloon, and the New Territories were calculated based on their respective proportion of the Hong Kong population in 2011. The estimated time to complete the questionnaire was approximately 10 minutes. The questionnaire included questions on demographic data and the use of smart phones and their related features. A total of 982 participants were interviewed, 46% of whom were male and 54% female. The participants were divided into the following two groups: the young-old (age 50-69) and the old-old (age 70 or above). The mean age was 67.93±10.386. The findings showed that, in comparison with the young-old group (age 50 to 69), a smaller percentage of the old-old group (70 and over) used smart phones and mobile messaging applications to communicate with others. There were no differences in patterns with regard to the type and frequency of the mobile applications being used. However, a smaller percentage of the old-old group had installed the mobile app by themselves and introduced the mobile app to others. This study reveals the behavioral patterns of the young-old and the old-old groups in the use of mobile devices to communicate. The young-old and old-old groups exhibited the same patterns in terms of the types and frequency of the mobile apps used; however, a smaller percentage of the old-old group used mobile apps to communicate. Different educational programs on the importance of social support should be established, and the promotional strategies for these programs need to be tailored to older adults

Variational method for learning Quantum Channels via Stinespring Dilation on neutral atom systems

The state $|\psi(t)\rangle$ of a closed quantum system evolves under the Schr\"{o}dinger equation, where the reversible evolution of the state is described by the action of a unitary operator $U(t)$ on the initial state $|\psi_0\rangle$, i.e.\ $|\psi(t)\rangle=U(t)|\psi_0\rangle$. However, realistic quantum systems interact with their environment, resulting in non-reversible evolutions, described by Lindblad equations. The solution of these equations give rise to quantum channels $\Phi_t$ that describe the evolution of density matrices according to $\rho(t)=\Phi_t(\rho_0)$, which often results in decoherence and dephasing of the state. For many quantum experiments, the time until which measurements can be done might be limited, e.g. by experimental instability or technological constraints. However, further evolution of the state may be of interest. For instance, to determine the source of the decoherence and dephasing, or to identify the steady state of the evolution. In this work, we introduce a method to approximate a given target quantum channel by means of variationally approximating equivalent unitaries on an extended system, invoking the Stinespring dilation theorem. We report on an experimentally feasible method to extrapolate the quantum channel on discrete time steps using only data on the first time steps. Our approach heavily relies on the ability to spatially transport entangled qubits, which is unique to the neutral atom quantum computing architecture. Furthermore, the method shows promising predictive power for various non-trivial quantum channels. Lastly, a quantitative analysis is performed between gate-based and pulse-based variational quantum algorithms.Comment: 11 pages, 7 figure

Theory of Light Emission in Sonoluminescence as Thermal Radiation

Based on the model proposed by Hilgenfeldt {\it at al.} [Nature {\bf 398}, 401 (1999)], we present here a comprehensive theory of thermal radiation in single-bubble sonoluminescence (SBSL). We first invoke the generalized Kirchhoff's law to obtain the thermal emissivity from the absorption cross-section of a multilayered sphere (MLS). A sonoluminescing bubble, whose internal structure is determined from hydrodynamic simulations, is then modelled as a MLS and in turn the thermal radiation is evaluated. Numerical results obtained from simulations for argon bubbles show that our theory successfully captures the major features observed in SBSL experiments.Comment: 17 pages, 20 figure

Angle-resolved photoemission spectra of graphene from first-principles calculations

Angle-resolved photoemission spectroscopy (ARPES) is a powerful experimental technique for directly probing electron dynamics in solids. The energy vs. momentum dispersion relations and the associated spectral broadenings measured by ARPES provide a wealth of information on quantum many-body interaction effects. In particular, ARPES allows studies of the Coulomb interaction among electrons (electron-electron interactions) and the interaction between electrons and lattice vibrations (electron-phonon interactions). Here, we report ab initio simulations of the ARPES spectra of graphene including both electron-electron and electron-phonon interactions on the same footing. Our calculations reproduce some of the key experimental observations related to many-body effects, including the indication of a mismatch between the upper and lower halves of the Dirac cone

Humor Therapy: Relieving Chronic Pain and Enhancing Happiness for Older Adults

The present study examined the effectiveness of a humor therapy program in relieving chronic pain, enhancing happiness and life satisfaction, and reducing loneliness among older persons with chronic pain. It was a quasiexperimental pretest-posttest controlled design. Older persons in a nursing home were invited to join an 8-week humor therapy program (experimental group), while those in another nursing home were treated as a control group and were not offered the program. There were 36 older people in the experimental group and 34 in the control group. Upon completion of the humor therapy program, there were significant decreases in pain and perception of loneliness, and significant increases in happiness and life satisfaction for the experimental group, but not for the control group. The use of humor therapy appears to be an effective nonpharmacological intervention. Nurses and other healthcare professionals could incorporate humor in caring for their patients

Tpeak-Tend, Tpeak-Tend/QT ratio and Tpeak-Tend dispersion for risk stratification in Brugada Syndrome:A systematic review and meta-analysis

Background: Brugada syndrome is an ion channelopathy that predisposes affected subjects to ventricular tachycardia/fibrillation (VT/VF), potentially leading to sudden cardiac death (SCD). Tpeak-Tend intervals, (Tpeak-Tend)/QT ratio and Tpeak-Tend dispersion have been proposed for risk stratification, but their predictive values in Brugada syndrome have been challenged recently. Methods: A systematic review and meta-analysis was conducted to examine their values in predicting arrhythmic and mortality outcomes in Brugada Syndrome. PubMed and Embase databases were searched until 1 May 2018, identifying 29 and 57 studies. Results: Nine studies involving 1740 subjects (mean age 45 years old, 80% male, mean follow-up duration was 68 ± 27 months) were included. The mean Tpeak-Tend interval was 98.9 ms (95% CI: 90.5-107.2 ms) for patients with adverse events (ventricular arrhythmias or SCD) compared to 87.7 ms (95% CI: 80.5-94.9 ms) for those without such events, with a mean difference of 11.9 ms (95% CI: 3.6-20.2 ms, P = 0.005; I2 = 86%). Higher (Tpeak-Tend)/QT ratios (mean difference = 0.019, 95% CI: 0.003-0.036, P = 0.024; I2 = 74%) and Tpeak-Tend dispersion (mean difference = 7.8 ms, 95% CI: 2.1-13.4 ms, P = 0.007; I2 = 80%) were observed for the event-positive group. Conclusion: Tpeak-Tend interval, (Tpeak-Tend)/QT ratio and Tpeak-Tend dispersion were higher in high-risk than low-risk Brugada subjects, and thus offer incremental value for risk stratification