17,971 research outputs found

    Validation of the English and Chinese versions of the Quick-FLIC quality of life questionnaire.

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    A useful measure of quality of life should be easy and quick to complete. Recently, we reported the development and validation of a shortened Chinese version of the Functional Living Index-Cancer (FLIC), which we called the Quick-FLIC. In the present study of 327 English-speaking and 221 Chinese-speaking cancer patients, we validated the English version of the Quick-FLIC and further assessed the Chinese version. The 11 Quick-FLIC items were administered alongside the 11 remaining items of the full FLIC, but there appeared to be little context effect. Validity of the English version of the Quick-FLIC was attested by its strong correlation with two other measures of quality of life, and its ability to detect differences between patients with different performance status and treatment status (each P<0.001). Its internal consistency (alpha=0.86) and test-retest reliability (intraclass correlation=0.76) were also satisfactory. The measure was responsive to changes in performance status (P<0.001). The Chinese version showed similar characteristics. The Quick-FLIC behaved in ways that are highly comparable with the FLIC, even though the Quick-FLIC comprised only 11 items whereas the FLIC comprised 22. Further research is required to see whether the use of shorter instruments can improve data quality and response rates, but the fact that shorter instruments place less burden on the patients is itself inherently important

    Data Management ofRFID-based Track-and-Trace Anti-counterfeiting in Apparel Supply Chain

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    With recent advancement in Radio Frequency Identification (RFID), RFID-based track-and-trace anti-counterfeiting has attracted considerable research interests. A track-and-trace anti-counterfeiting system requires an integral and reliable electronic pedigree (e-pedigree) to ensure high product visibility along the supply chain. With the continuous movements of large volumes of products along the supply chain, huge amounts of RFID data would be inevitably generated, posing great challenges to system development and operation. As such, the front-end RFID data should be well-formatted for efficient capturing, filtering, and synchronization in a logical and reliable way, so that the accumulated e-pedigree would be complete and trustworthy for subsequent product authentication. In this paper, we present an innovative track-and-trace anti-counterfeiting system for apparel products, and discuss a number of key data management issues, such as e-pedigree formatting, data synchronization, and traceability / visibility control. A data format of e-pedigree for full traceability of garments is proposed to support products authentication in item-level, products antilost in pallet-level and products status prediction in batch-level. Based on this format, a three-step mechanism of data synchronization is established to ensure e-pedigree integrity. To avoid possible leakage/falsification of e-pedigree data, an RBACbased access control is proposed as an auxiliary module of the anti-counterfeiting system.published_or_final_versio

    Comparison of chemical profiles and effectiveness between Erxian decoction and mixtures of decoctions of its individual herbs : a novel approach for identification of the standard chemicals

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    Acknowledgements This study was partially supported by grants from the Seed Funding Programme for Basic Research (Project Number 201211159146 and 201411159213), the University of Hong Kong. We thank Mr Keith Wong and Ms Cindy Lee for their technical assistances.Peer reviewedPublisher PD

    Some Issues in a Gauge Model of Unparticles

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    We address in a recent gauge model of unparticles the issues that are important for consistency of a gauge theory, i.e., unitarity and Ward identity of physical amplitudes. We find that non-integrable singularities arise in physical quantities like cross section and decay rate from gauge interactions of unparticles. We also show that Ward identity is violated due to the lack of a dispersion relation for charged unparticles although the Ward-Takahashi identity for general Green functions is incorporated in the model. A previous observation that the unparticle's (with scaling dimension d) contribution to the gauge boson self-energy is a factor (2-d) of the particle's has been extended to the Green function of triple gauge bosons. This (2-d) rule may be generally true for any point Green functions of gauge bosons. This implies that the model would be trivial even as one that mimics certain dynamical effects on gauge bosons in which unparticles serve as an interpolating field.Comment: v1:16 pages, 3 figures. v2: some clarifications made and presentation improved, calculation and conclusion not modified; refs added and updated. Version to appear in EPJ

    Are Asians comfortable with discussing death in health valuation studies? A study in multi-ethnic Singapore

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    BACKGROUND To characterize ease in discussing death (EID) and its influence on health valuation in a multi-ethnic Asian population and to determine the acceptability of various descriptors of death and "pits"/"all-worst" in health valuation. METHODS In-depth interviews (English or mother-tongue) among adult Chinese, Malay and Indian Singaporeans selected to represent both genders and a wide range of ages/educational levels. Subjects rated using 0–10 visual analogue scales (VAS): (1) EID, (2) acceptability of 8 descriptors for death, and (3) appropriateness of "pits" and "all-worst" as descriptors for the worst possible health state. Subjects also valued 3 health states using VAS followed by time trade-off (TTO). The influence of sociocultural variables on EID and these descriptors was studied using univariable analyses and multiple linear regression (MLR). The influence of EID on VAS/TTO utilities with adjustment for sociocultural variables was assessed using MLR. RESULTS Subjects (n = 63, 35% Chinese, 32% Malay, median age 44 years) were generally comfortable with discussing death (median EID: 8.0). Only education significantly influenced EID (p = 0.045). EID correlated weakly with VAS/TTO scores (range: VAS: -0.23 to 0.07; TTO: -0.14 to 0.11). All subjects felt "passed away", "departed" and "deceased" were most acceptable (median acceptability: 8.0) while "sudden death" and "immediate death" were least acceptable (median acceptability: 5.0). Subjects clearly preferred "all-worst" to "pits" (63% vs. 19%, p < 0.001). CONCLUSION Singaporeans were generally comfortable with discussing death and had clear preferences for several descriptors of death and for "all-worst". EID is unlikely to influence health preference measurement in health valuation studies

    Slip energy barriers in aluminum and implications for ductile versus brittle behavior

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    We conisder the brittle versus ductile behavior of aluminum in the framework of the Peierls-model analysis of dislocation emission from a crack tip. To this end, we perform first-principles quantum mechanical calculations for the unstable stacking energy γus\gamma_{us} of aluminum along the Shockley partial slip route. Our calculations are based on density functional theory and the local density approximation and include full atomic and volume relaxation. We find that in aluminum γus=0.224\gamma_{us} = 0.224 J/m2^2. Within the Peierls-model analysis, this value would predict a brittle solid which poses an interesting problem since aluminum is typically considered ductile. The resolution may be given by one of three possibilites: (a) Aluminum is indeed brittle at zero temperature, and becomes ductile at a finite temperature due to motion of pre-existing dislocations which relax the stress concentration at the crack tip. (b) Dislocation emission at the crack tip is itself a thermally activated process. (c) Aluminum is actually ductile at all temperatures and the theoretical model employed needs to be significantly improved in order to resolve the apparent contradiction.Comment: 4 figures (not included; send requests to [email protected]

    Sprinkle Your Investment Portfolio with Water!

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    This paper investigates the profitability of water-related investments and their diversification benefits in a portfolio context. Motivated by the need to understand whether or not water indices and water funds are desirable vehicles for investment, we analyse the performance of a major water index independently, as well as within portfolios. Our results indicate that the water asset class outperforms traditional asset classes, and has the capacity to produce diversification effects in portfolios primarily comprised of listed equity and bond assets. In addition, our study suggests that the diversification benefits of the water asset class are likely to be a result of its superior performance over the stock benchmark, rather than its low correlation with traditional asset classes. Our study provides a valuable contribution to the small, yet growing body of literature on water investments

    Quantum theory for mesoscopic electric circuits

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    A quantum theory for mesoscopic electric circuits in accord with the discreteness of electric charges is proposed. On the basis of the theory, Schr\"{o}dinger equation for the quantum LC-design and L-design is solved exactly. The uncertainty relation for electric charge and current is obtained and a minimum uncertainty state is solved. By introducing a gauge field, a formula for persistent current arising from magnetic flux is obtained from a new point of view.Comment: revtex, no figure

    Self-consistent scattering theory of transport and output characteristics of quantum cascade lasers

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    Electron transport in GaAs/AlGaAs quantum cascade lasers operating in midinfrared is calculated self-consistently using an intersubband scattering model. Subband populations and carrier transition rates are calculated and all relevant electron-LO phonon and electron-electron scatterings between injector/collector, active region, and continuum resonance levels are included. The calculated carrier lifetimes and subband populations are then used to evaluate scattering current densities, injection efficiencies, and carrier backflow into the active region for a range of operating temperatures. From the calculated modal gain versus total current density dependencies the output characteristics, in particular the gain coefficient and threshold current, are extracted. For the original GaAs/Al0.33Ga0.67As quantum cascade structure [C. Sirtori , Appl. Phys. Lett. 73, 3486 (1998)] these are found to be g=11.3 cm/kA and J(th)=6+/-1 kA/cm(2) (at T=77 K), and g=7.9 cm/kA and J(th)=10+/-1 kA/cm(2) (at T=200 K), in good agreement with the experiment. Calculations shows that threshold cannot be achieved in this structure at T=300 K, due to the small gain coefficient and the gain saturation effect, also in agreement with experimental findings. The model thus promises to be a powerful tool for the prediction and optimization of new, improved quantum cascade structures. © 2002 American Institute of Physics
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