199 research outputs found
An Apparent Redshift Dependence of Quasar Continuum: Implication for Cosmic Dust Extinction?
We investigate the luminosity and redshift dependence of the quasar continuum
by means of composite spectrum using a large non-BAL radio-quiet quasar sample
drawn from the Sloan Digital Sky Survey. Quasar continuum slopes in the UV-Opt
band are measured at two different wavelength ranges, i.e.,
() and () derived
from power law fitting. Generally, the UV spectra slope becomes harder (higher
) towards higher bolometric luminosity. On the other hand, when
quasars are further grouped into luminosity bins, we find both
and show significant anti-correlation with redshift (i.e.,
quasar continuum becomes redder towards higher redshift). We suggest that the
cosmic dust extinction is very likely the cause of this observed
relation. We build a simple cosmic dust extinction model to quantify the
observed reddening tendency and find an effective dust density at . The other possibilities that could produce
such a reddening effect have also been discussed.Comment: 6 pages, 5 figures; published in ApJ
Intergenerational Earnings Mobility in Singapore and the United States
This study compared intergenerational earnings mobility in Singapore and the United States by replicating the limitations in the Singapore National Youth Survey on the U.S. Panel Study of Income Dynamics. The mean estimated earnings elasticities are almost identical: 0.26 in Singapore and 0.27 in the United States. Transformed to 0.45 and 0.47 respectively to reflect permanent status, mobility in the two countries is moderately low compared internationally. The finding of similar mobility is not surprising given that the economic realities, welfare systems, education regimes, and labor structures in the two countries are similar. Policy makers face the daunting challenge of overcoming immobility and inequality while maintaining global competitiveness.Intergenerational earnings mobility; Singapore; United States
ANALYSIS OF THE FACTORS AFFECTING PIANISTS’ MEMORIZATION DURING PERFORMANCE AND METHODS TO IMPROVE THE EFFICIENCY OF MEMORIZATION
Pianists can often experience hardships associated with the memorization of musical works intended for the stage. Deficiencies in the efficacy of memorization have always seemed to plague pianists’ performance capabilities. The purpose of this research was to analyze the factors affecting pianists’ memorization during performance and attempt to explore more valuable and efficient methods to achieve adequate cognitive retention of material. Additionally, this research explores the extrinsic and intrinsic factors that have an impact on pianists’ capabilities to perform repertoire memorized. The intention is to locate the connections between particular stylistic traits in the repertoire and the celerity of memorization. An examination of these stylistic traits and the compositional era of given repertoire will aid in the discovery of whether or not these factors affect the overall speed of the memorization process. That will then lead to a survey of appropriate practice methods that may assist in pianists’ efficiency of memorization. In the end, specific practice methods will be employed through a pedagogical lens with the intention of enhancing the efficacy of memorization. This research will aim to serve as a guide to provide young pianists with the tools needed to avoid memory slips and practical methods to achieve effective memorization
All-condition pulse detection using a magnetic sensor
A plethora of wearable devices have been developed or commercialized for
continuous non-invasive monitoring of physiological signals that are crucial
for preventive care and management of chronic conditions. However, most of
these devices are either sensitive to skin conditions or its interface with the
skin due to the requirement that the external stimuli such as light or
electrical excitation must penetrate the skin to detect the pulse. This often
results in large motion artefacts and unsuitability for certain skin
conditions. Here, we demonstrate a simple fingertip-type device which can
detect clear pulse signals under all conditions, including fingers covered by
opaque substances such as a plaster or nail polish, or fingers immersed in
liquid. The device has a very simple structure, consisting of only a pair of
magnets and a magnetic sensor. We show through both experiments and simulations
that the detected pulsation signals correspond directly to the magnet
vibrations caused by blood circulation, and therefore, in addition to heartrate
detection, the proposed device can also be potentially used for blood pressure
measurement
Volatility Timing of Funds under CPF Investment Scheme: A GARCH Model Approach
Master'sMASTER OF SOCIAL SCIENCE
Volatility timing in CPF investment funds in Singapore: Do they outperform non-CPF funds?
The purpose of this study is to examine the volatility-timing performance of Singapore-based funds under the Central Provident Fund (CPF) Investment Scheme and non-CPF linked funds by taking into account the currency risk effect on internationally managed funds. In particular, we empirically assess whether the funds under the CPF Investment Scheme outperform non-CPF funds by examining the volatility-timing performance associated with these funds. The volatility-timing ability of CPF funds will provide the CPF board with a new method for risk classification. We employ the GARCH models and modified factor models to capture the response of funds to market abnormal conditional volatility including the weekday effect. The SMB and HML factors for non- US based funds are constructed from stock market data to exclude the contribution of the size effect and the BE/ME effect. The results show that volatility timing is one of the factors contributing to the excess return of funds. However, funds’ volatility-timing seems to be country-specific. Most of the Japanese equity funds and global equity funds under the CPF Investment Scheme are found to have the ability of volatility timing. This finding contrasts with the existing studies on Asian, ex-Japan funds and Greater China funds. Moreover, there is no evidence that funds under the CPF Investment Scheme show a better group performance of volatility timing
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