19,331 research outputs found
Generation of the auroral kilometric radiation
For abstract, see A82-3554
Covariant hamiltonian dynamics
We discuss the covariant formulation of the dynamics of particles with
abelian and non-abelian gauge charges in external fields. Using this
formulation we develop an algorithm for the construction of constants of
motion, which makes use of a generalization of the concept of Killing vectors
and tensors in differential geometry. We apply the formalism to the motion of
classical charges in abelian and non-abelian monopole fieldsComment: 15 pages, no figure
Ultrafast, laser-scanning time-stretch microscopy with visible light
published_or_final_versio
Bifurcation behavior of SPICE simulations of switching converters : a systematic analysis of erroneous results
Author name used in this publication: Chi K. Tse2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Erroneous results from SPICE simulations of switching converters : a dynamical system viewpoint
Author name used in this publication: Chi K. TseRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Dynamical Synapses Enhance Neural Information Processing: Gracefulness, Accuracy and Mobility
Experimental data have revealed that neuronal connection efficacy exhibits
two forms of short-term plasticity, namely, short-term depression (STD) and
short-term facilitation (STF). They have time constants residing between fast
neural signaling and rapid learning, and may serve as substrates for neural
systems manipulating temporal information on relevant time scales. The present
study investigates the impact of STD and STF on the dynamics of continuous
attractor neural networks (CANNs) and their potential roles in neural
information processing. We find that STD endows the network with slow-decaying
plateau behaviors-the network that is initially being stimulated to an active
state decays to a silent state very slowly on the time scale of STD rather than
on the time scale of neural signaling. This provides a mechanism for neural
systems to hold sensory memory easily and shut off persistent activities
gracefully. With STF, we find that the network can hold a memory trace of
external inputs in the facilitated neuronal interactions, which provides a way
to stabilize the network response to noisy inputs, leading to improved accuracy
in population decoding. Furthermore, we find that STD increases the mobility of
the network states. The increased mobility enhances the tracking performance of
the network in response to time-varying stimuli, leading to anticipative neural
responses. In general, we find that STD and STP tend to have opposite effects
on network dynamics and complementary computational advantages, suggesting that
the brain may employ a strategy of weighting them differentially depending on
the computational purpose.Comment: 40 pages, 17 figure
Commercial property markets and property cycles in Chinese cities
This paper uses interview data to explore and examines property markets in three
Chinese cities with the focus placed on the emergence of the commercial property
markets and the government-market interplay, noting the market formation process
and cycles that are ‘unexpected’ in a transitional economy. The research identified
varying opinions and perceptions among key stake-holders about cycles in China’s
emerging commercial property markets. Interviews in the three cities suggested a
spectrum of factors that may substantially affect the stability of China’s office
markets. A cross-sectional comparison of the three cities has revealed a similar
pattern of cyclical behaviour highlighting structural change and state intervention with
leads-and-lags, in spite of the dispersion in geography, culture and market maturity.
The various views offered about market mechanism and cyclical behaviour represent
varying levels of market maturity. These brief insights offer an opportunity to develop
an alternative approach to measure property market conditions in emerging or
immature markets such as China.published_or_final_versio
Development of Evidence-Based Chinese Medicine Clinical Service Recommendations for Cancer Palliative Care Using Delphi Approach Based on the Evidence to Decision Framework.
Objectives: Existing evidence supports the use of certain Chinese medicine (CM) interventions for symptom management among palliative cancer patients. However, evidence-based service recommendations tailored to the local context are needed for CM planning and implementation. In response, we aimed to establish consensus on CM clinical service recommendations for cancer palliative care among Hong Kong experts. Methods: Seven CM interventions showing statistically significant favorable results in existing systematic reviews (SRs) and overviews of SRs were subjected to a GRADE-ADOLOPMENT-based 2-round Delphi survey. Twelve Hong Kong experts in cancer palliative care, including conventionally trained physicians, CM practitioners, and nurses (n = 4 from each category), were invited to participate. Use of the Evidence to Decision framework within the GRADE-ADOLOPMENT approach enabled experts to consider aspects of problem priority, benefits, harms, equity, acceptability, and feasibility when making CM recommendations in cancer palliative care. Results: Three evidence-based CM interventions reached positive consensus as service recommendations, namely: (1) acupuncture for reducing fatigue among palliative cancer patients; (2) acupressure for reducing fatigue among palliative cancer patients; and (3) moxibustion for reducing nausea and vomiting among patients receiving chemotherapy. Median rating of recommendation ranged from 2.5 to 3.0 (interquartile range = 0.00-1.00) on a 4-point Likert-type scale, and the percentage agreement ranged from 83.4% to 91.7%. Conclusions: The GRADE-ADOLOPMENT approach facilitates a consensus-based process of reaching 3 evidence-based CM recommendations for cancer palliative care. Future studies may develop tailored strategies to implement these recommendations in the Hong Kong health system
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