744 research outputs found
Adjusted Empirical Likelihood for Long-memory Time Series Models
Empirical likelihood method has been applied to short-memory time series
models by Monti (1997) through the Whittle's estimation method. Yau (2012)
extended this idea to long-memory time series models. Asymptotic distributions
of the empirical likelihood ratio statistic for short and long-memory time
series have been derived to construct confidence regions for the corresponding
model parameters. However, computing profile empirical likelihood function
involving constrained maximization does not always have a solution which leads
to several drawbacks. In this paper, we propose an adjusted empirical
likelihood procedure to modify the one proposed by Yau (2012) for
autoregressive fractionally integrated moving average (ARFIMA) model. It
guarantees the existence of a solution to the required maximization problem as
well as maintains same asymptotic properties obtained by Yau (2012).
Simulations have been carried out to illustrate that the adjusted empirical
likelihood method for different long-time series models provides better
confidence regions and coverage probabilities than the unadjusted ones,
especially for small sample sizes
Development of storm water quality improvement strategy plan for local city councils in Western Australia
The aim of this study was to develop a storm water quality improvement strategy plan (WQISP) which assists managers and decision makers of local city councils in enhancing their activities to improve regional water quality. City of Gosnells in Western Australia has been considered as a case study. The procedure on developing the WQISP consists of reviewing existing water quality data, identifying water quality issues in the study areas and developing a decision making tool for the officers, managers and decision makers. It was found that land use type is the main factor affecting the water quality. Therefore, activities, sources and pollutants related to different land use types including residential, industrial, agricultural and commercial are given high importance during the study. Semi-structured interviews were carried out with coordinators of different management sections of the regional councils in order to understand the associated management framework and issues. The issues identified from these interviews were used in preparing the decision making tool. Variables associated with the defined "value versus threat" decision making tool are obtained from the intensive literature review. The main recommendations provided for improvement of water quality in local city councils, include non-structural, structural and management controls and potential impacts of climate change
The use of remote sensing data for drought assessment and monitoring in southwest Asia
Drought / Monitoring / Indicators / Assessment / Remote sensing / Asia
Updated evaluation of potential ultra-low Q value -decay candidates
"Ultra-low" Q value decays are referred to as such due to their low
decay energies of less than 1 keV. Such a low energy decay is possible
when the parent nucleus decays into an excited state in the daughter, with an
energy close to that of the Q value. These decays are of interest as potential
new candidates for neutrino mass determination experiments and as a testing
ground for studies of atomic interference effects in the nuclear decay process.
In this paper, we provide an updated evaluation of atomic mass data and nuclear
energy level data to identify potential ultra-low Q value decay
candidates. For many of these candidates, more precise and accurate atomic mass
data is needed to determine if the Q value of the potential ultra-low decay
branch is energetically allowed and in fact ultra-low. The precise atomic mass
measurements can be achieved via Penning trap mass spectrometry
Towards portable muography with small-area, gas-tight glass Resistive Plate Chambers
Imaging techniques that use atmospheric muons, collectively named under the
neologism "muography", have seen a tremendous growth in recent times, mainly
due to their diverse range of applications. The most well-known ones include
but are not limited to: volcanology, archaeology, civil engineering, nuclear
reactor monitoring, nuclear waste characterization, underground mapping, etc.
These methods are based on the attenuation or deviation of muons to image large
and/or dense objects where conventional techniques cannot work or their use
becomes challenging.
In this context, we have constructed a muography telescope based on "mini
glass-RPC planes" following a design similar to the glass-RPC detectors
developed by the CALICE Collaboration and used by the TOMUVOL experiment in the
context of volcano radiography, but with smaller active area (16 16
cm). The compact size makes it an attractive choice with respect to other
detectors previously employed for imaging on similar scales. An important
innovation in this design is that the detectors are sealed. This makes the
detector more portable and solves the usual safety and logistic issues for gas
detectors operated underground and/or inside small rooms. This paper provides
an overview on our guiding principles, the detector development and our
operational experiences. Drawing on the lessons learnt from the first
prototype, we also discuss our future direction for an improved second
prototype, focusing primarily on a recently adopted serigraphy technique for
the resistive coating of the glass plates.Comment: 8 pages, 7 figures, XV Workshop on Resistive Plate Chambers and
Related Detectors (RPC2020
Green intraprenurial flexibility towards sustaining competitive advantage: A case of South Asian context
This study explores how green based intrapreneurial flexibility affects sustainable business performance of the Sri Lankan hotel industry. A survey was administered to a random sample of senior managers of hotels in Sri Lanka. Linear regression analysis revealed a significant path coefficient which explained green based intrapreneurial flexibility positively influenced sustainable competitive advantage. The findings suggest that hotel industry policy makers develop green specific intrapreneurial capabilities so that they can quickly adapt their green based product and service offerings in responding to changes of the green market requirements by focusing on green based new venture creation, green innovation, green related self-renewal exercises, and eco-friendly proactive decision making in order to sustain their competitive advantage from green initiatives
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