118 research outputs found
Opening up public data should be an urgent priority for the government and could lead to considerable economic benefits
There is no longer a reasonable justification for keeping publicly funded data under lock and key. With the government ostensibly committed to transparency, Chris Yiu argues that opening up public data is a must, and could have solid economic and productive benefits
Semiparametric posterior corrections
We present a new approach to semiparametric inference using corrected
posterior distributions. The method allows us to leverage the adaptivity,
regularization and predictive power of nonparametric Bayesian procedures to
estimate low-dimensional functionals of interest without being restricted by
the holistic Bayesian formalism. Starting from a conventional nonparametric
posterior, we target the functional of interest by transforming the entire
distribution with a Bayesian bootstrap correction. We provide conditions for
the resulting to possess calibrated frequentist
properties and specialize the results for several canonical examples: the
integrated squared density, the mean of a missing-at-random outcome, and the
average causal treatment effect on the treated. The procedure is
computationally attractive, requiring only a simple, efficient post-processing
step that can be attached onto any arbitrary posterior sampling algorithm.
Using the ACIC 2016 causal data analysis competition, we illustrate that our
approach can outperform the existing state-of-the-art through the propagation
of Bayesian uncertainty.Comment: 53 page
Emerging Ecology of a Sign Bilingualism and Co-enrollment Classroom: a Qualitative Analysis
This study documents the views and attitudes of stakeholders of the Hong Kongâs Sign Bilingualism and Co-enrollment (SLCO) Education Programme established in 2006, to identify an emerging ecology based on the SLCO classrooms in a primary school in which deaf and hard-of-hearing (DHH) as well as hearing participants, teachers and students alike, collaborated to create an inclusive culture in the school environment. Qualitative data were collected using two focus group discussions, each with six DHH students and six hearing students, and individual interviews with eleven parents of DHH and hearing students and six Deaf and hearing teachers. The data generated seven themes: positive impacts of sign language (i.e. HKSL), translanguaging, differences in English and Chinese achievement, positive attitudes towards co-enrollment, increase in studentsâ self-confidence, friendship and equal partnership, and importance and challenges of co-planning. Analysing these themes within the framework of evaluating inclusive education along the parameters of participation, achievement, and value of person as advanced in Anderson, Boyle and Deppeler (2014), we identified six dimensions to characterise the inclusive ecology of the SLCO classroom
An Algorithm for Modelling Escalator Fixed Loss Energy for PHM and sustainable energy usage
Prognostic Health Management (PHM) is designed to assess and monitor the
health status of systems, anticipate the onset of potential failure, and
prevent unplanned downtime. In recent decades, collecting massive amounts of
real-time sensor data enabled condition monitoring (CM) and consequently,
detection of abnormalities to support maintenance decision-making.
Additionally, the utilization of PHM techniques can support energy
sustainability efforts by optimizing energy usage and identifying opportunities
for energy-saving measures. Escalators are efficient machines for transporting
people and goods, and measuring energy consumption in time can facilitate PHM
of escalators. Fixed loss energy, or no-load energy, of escalators denotes the
energy consumption by an unloaded escalator. Fixed loss energy varies over time
indicating varying operating conditions. In this paper, we propose to use
escalators' fixed loss energy for PHM. We propose an approach to compute daily
fixed loss energy based on energy consumption sensor data. The proposed
approach is validated using a set of experimental data. The advantages and
disadvantages of each approach are also presented, and recommendations are
given. Finally, to illustrate PHM, we set up an EWMA chart for monitoring the
fixed loss over time and demonstrate the potential in reducing energy costs
associated with escalator operation
Remaining Useful Life Modelling with an Escalator Health Condition Analytic System
The refurbishment of an escalator is usually linked with its design life as
recommended by the manufacturer. However, the actual useful life of an
escalator should be determined by its operating condition which is affected by
the runtime, workload, maintenance quality, vibration, etc., rather than age
only. The objective of this project is to develop a comprehensive health
condition analytic system for escalators to support refurbishment decisions.
The analytic system consists of four parts: 1) online data gathering and
processing; 2) a dashboard for condition monitoring; 3) a health index model;
and 4) remaining useful life prediction. The results can be used for a)
predicting the remaining useful life of the escalators, in order to support
asset replacement planning and b) monitoring the real-time condition of
escalators; including alerts when vibration exceeds the threshold and signal
diagnosis, giving an indication of possible root cause (components) of the
alert signal.Comment: 14 pages, 12 figures, 7 table
A Retinotopic Basis for the Division of High-Level Scene Processing between Lateral and Ventral Human Occipitotemporal Cortex
In humans, there is a repeated category-selective organization across the lateral and ventral surfaces of the occipitotemporal cortex. This apparent redundancy is often explained as a feedforward hierarchy, with processing within lateral areas preceding the processing within ventral areas. Here, we tested the alternative hypothesis that this structure better reflects distinct high-level representations of the upper (ventral surface) and lower (lateral surface) contralateral quadrants of the visual field, consistent with anatomical projections from early visual areas to these surfaces in monkey. Using complex natural scenes, we provide converging evidence from three independent functional imaging and behavioral studies. First, population receptive field mapping revealed strong biases for the contralateral upper and lower quadrant within the ventral and lateral scene-selective regions, respectively. Second, these same biases were observed in the position information available both in the magnitude and multivoxel response across these areas. Third, behavioral judgments of a scene property strongly represented within the ventral scene-selective area (open/closed), but not another equally salient property (manmade/natural), were more accurate in the upper than the lower field. Such differential representation of visual space poses a substantial challenge to the idea of a strictly hierarchical organization between lateral and ventral scene-selective regions. Moreover, such retinotopic biases seem to extend beyond these regions throughout both surfaces. Thus, the large-scale organization of high-level extrastriate cortex likely reflects the need for both specialized representations of particular categories and constraints from the structure of early vision. SIGNIFICANCE STATEMENT One of the most striking findings in fMRI has been the presence of matched category-selective regions on the lateral and ventral surfaces of human occipitotemporal cortex. Here, we focus on scene-selective regions and provide converging evidence for a retinotopic explanation of this organization. Specifically, we demonstrate that scene-selective regions exhibit strong biases for different portions of the visual field, with the lateral region representing the contralateral lower visual field and the ventral region the contralateral upper visual field. These biases are consistent with the retinotopy found in the early visual areas that lie directly antecedent to category-selective areas on both surfaces. Furthermore, these biases extend beyond scene-selective cortex and provide a retinotopic basis for the large-scale organization of occipitotemporal cortex
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