Abstract: The problem of estimating time-varying regression is
inevitably concerned with the necessity to choose the appropriate
level of model volatility - ranging from the full stationarity of instant
regression models to their absolute independence of each other. In the
stationary case the number of regression coefficients to be estimated
equals that of regressors, whereas the absence of any smoothness
assumptions augments the dimension of the unknown vector by the
factor of the time-series length. The Akaike Information Criterion
is a commonly adopted means of adjusting a model to the given
data set within a succession of nested parametric model classes,
but its crucial restriction is that the classes are rigidly defined by
the growing integer-valued dimension of the unknown vector. To
make the Kullback information maximization principle underlying the
classical AIC applicable to the problem of time-varying regression
estimation, we extend it onto a wider class of data models in which
the dimension of the parameter is fixed, but the freedom of its values
is softly constrained by a family of continuously nested a priori
probability distributions.
Abstract: To evaluate genetic variation of wheat (Triticum
aestivum) affected by heat and drought stress on eight Australian
wheat genotypes that are parents of Doubled Haploid (HD) mapping
populations at the vegetative stage, the water stress experiment was
conducted at 65% field capacity in growth room. Heat stress
experiment was conducted in the research field under irrigation over
summer. Result show that water stress decreased dry shoot weight
and RWC but increased osmolarity and means of Fv/Fm values in all
varieties except for Krichauff. Krichauff and Kukri had the
maximum RWC under drought stress. Trident variety was shown
maximum WUE, osmolarity (610 mM/Kg), dry mater, quantum yield
and Fv/Fm 0.815 under water stress condition. However, the
recovery of quantum yield was apparent between 4 to 7 days after
stress in all varieties. Nevertheless, increase in water stress after that
lead to strong decrease in quantum yield. There was a genetic
variation for leaf pigments content among varieties under heat stress.
Heat stress decreased significantly the total chlorophyll content that
measured by SPAD. Krichauff had maximum value of Anthocyanin
content (2.978 A/g FW), chlorophyll a+b (2.001 mg/g FW) and
chlorophyll a (1.502 mg/g FW). Maximum value of chlorophyll b
(0.515 mg/g FW) and Carotenoids (0.234 mg/g FW) content
belonged to Kukri. The quantum yield of all varieties decreased
significantly, when the weather temperature increased from 28 ÔùªC to
36 ÔùªC during the 6 days. However, the recovery of quantum yield
was apparent after 8th day in all varieties. The maximum decrease
and recovery in quantum yield was observed in Krichauff. Drought
and heat tolerant and moderately tolerant wheat genotypes were
included Trident, Krichauff, Kukri and RAC875. Molineux, Berkut
and Excalibur were clustered into most sensitive and moderately
sensitive genotypes. Finally, the results show that there was a
significantly genetic variation among the eight varieties that were
studied under heat and water stress.
Abstract: The purpose of this paper is to perform a multidisciplinary design and analysis (MDA) of honeycomb panels used in the satellites structural design. All the analysis is based on clamped-free boundary conditions. In the present work, detailed finite element models for honeycomb panels are developed and analysed. Experimental tests were carried out on a honeycomb specimen of which the goal is to compare the previous modal analysis made by the finite element method as well as the existing equivalent approaches. The obtained results show a good agreement between the finite element analysis, equivalent and tests results; the difference in the first two frequencies is less than 4% and less than 10% for the third frequency. The results of the equivalent model presented in this analysis are obtained with a good accuracy. Moreover, investigations carried out in this research relate to the honeycomb plate modal analysis under several aspects including the structural geometrical variation by studying the various influences of the dimension parameters on the modal frequency, the variation of core and skin material of the honeycomb. The various results obtained in this paper are promising and show that the geometry parameters and the type of material have an effect on the value of the honeycomb plate modal frequency.
Abstract: Automatic segmentation of skin lesions is the first step
towards development of a computer-aided diagnosis of melanoma.
Although numerous segmentation methods have been developed,
few studies have focused on determining the most discriminative
and effective color space for melanoma application. This paper
proposes a novel automatic segmentation algorithm using color space
analysis and clustering-based histogram thresholding, which is able to
determine the optimal color channel for segmentation of skin lesions.
To demonstrate the validity of the algorithm, it is tested on a set of 30
high resolution dermoscopy images and a comprehensive evaluation
of the results is provided, where borders manually drawn by four
dermatologists, are compared to automated borders detected by the
proposed algorithm. The evaluation is carried out by applying three
previously used metrics of accuracy, sensitivity, and specificity and
a new metric of similarity. Through ROC analysis and ranking the
metrics, it is shown that the best results are obtained with the X and
XoYoR color channels which results in an accuracy of approximately
97%. The proposed method is also compared with two state-ofthe-
art skin lesion segmentation methods, which demonstrates the
effectiveness and superiority of the proposed segmentation method.
Abstract: A filter is used to remove undesirable frequency information from a dynamic signal. This paper shows that the Znotch filter filtering technique can be applied to remove the noise nuisance from a machining signal. In machining, the noise components were identified from the sound produced by the operation of machine components itself such as hydraulic system, motor, machine environment and etc. By correlating the noise components with the measured machining signal, the interested components of the measured machining signal which was less interfered by the noise, can be extracted. Thus, the filtered signal is more reliable to be analysed in terms of noise content compared to the unfiltered signal. Significantly, the I-kaz method i.e. comprises of three dimensional graphical representation and I-kaz coefficient, Z∞ could differentiate between the filtered and the unfiltered signal. The bigger space of scattering and the higher value of Z∞ demonstrated that the signal was highly interrupted by noise. This method can be utilised as a proactive tool in evaluating the noise content in a signal. The evaluation of noise content is very important as well as the elimination especially for machining operation fault diagnosis purpose. The Z-notch filtering technique was reliable in extracting noise component from the measured machining signal with high efficiency. Even though the measured signal was exposed to high noise disruption, the signal generated from the interaction between cutting tool and work piece still can be acquired. Therefore, the interruption of noise that could change the original signal feature and consequently can deteriorate the useful sensory information can be eliminated.
Abstract: Several models have been introduced so far for single
electron box, SEB, which all of them were restricted to DC response
and or low temperature limit. In this paper we introduce a new time
dependent, high temperature analytical model for SEB for the first
time. DC behavior of the introduced model will be verified against
SIMON software and its time behavior will be verified against a
newly published paper regarding step response of SEB.
Abstract: This paper deals with the localization of the wideband sources. We develop a new approach for estimating the wide band sources parameters. This method is based on the high order statistics of the recorded data in order to eliminate the Gaussian components from the signals received on the various hydrophones.In fact the noise of sea bottom is regarded as being Gaussian. Thanks to the coherent signal subspace algorithm based on the cumulant matrix of the received data instead of the cross-spectral matrix the wideband correlated sources are perfectly located in the very noisy environment. We demonstrate the performance of the proposed algorithm on the real data recorded during an underwater acoustics experiments.
Abstract: In this paper the design of maximally flat linear phase
finite impulse response (FIR) filters is considered. The problem is
handled with totally two different approaches. The first one is
completely deterministic numerical approach where the problem is
formulated as a Linear Complementarity Problem (LCP). The other
one is based on a combination of Markov Random Fields (MRF's)
approach with messy genetic algorithm (MGA). Markov Random
Fields (MRFs) are a class of probabilistic models that have been
applied for many years to the analysis of visual patterns or textures.
Our objective is to establish MRFs as an interesting approach to
modeling messy genetic algorithms. We establish a theoretical result
that every genetic algorithm problem can be characterized in terms of
a MRF model. This allows us to construct an explicit probabilistic
model of the MGA fitness function and introduce the Ising MGA.
Experimentations done with Ising MGA are less costly than those
done with standard MGA since much less computations are involved.
The least computations of all is for the LCP. Results of the LCP,
random search, random seeded search, MGA, and Ising MGA are
discussed.
Abstract: In this paper, we argue that Design research is basic to countries- national productivity and competition agendas at the same time that vagaries of research training presents as one of the barriers faced by Design Higher Degree by Research students in engaging those agendas. We argue that, given industry requirements for research-trained recruits, students have the right to expect that research training will provide the foundations of a successful career on an academic or research pathway or a professional pathway, but that universities have yet to address problems in their provision of research training for Design doctoral students. We suggest that to facilitate this, rigorous research conducted on the provision of Doctoral programs in Design would serve to inform future activities in Design research in productive ways.
Abstract: Post growth annealing of solution grown ZnO
nanowire array is performed under controlled oxygen ambience. The
role of annealing over surface defects and their consequence on
dark/photo-conductivity and photosensitivity of nanowire array is
investigated. Surface defect properties are explored using various
measurement tools such as contact angle, photoluminescence, Raman
spectroscopy and XPS measurements. The contact angle of the NW
films reduces due to oxygen annealing and nanowire film surface
changes from hydrophobic (96°) to hydrophilic (16°). Raman and
XPS spectroscopy reveal that oxygen annealing improves the crystal
quality of the nanowire films. The defect band emission intensity
(relative to band edge emission, ID/IUV) reduces from 1.3 to 0.2 after
annealing at 600 °C at 10 SCCM flow of oxygen. An order
enhancement in dark conductivity is observed in O2 annealed
samples, while photoconductivity is found to be slightly reduced due
to lower concentration of surface related oxygen defects.
Abstract: Gas hydrates can agglomerate and block multiphase oil and gas pipelines when water is present at hydrate forming conditions. Using "Cold Flow Technology", the aim is to condition gas hydrates so that they can be transported as a slurry mixture without a risk of agglomeration. During the pipeline shut down however, hydrate particles may settle in bends and build hydrate plugs. An experimental setup has been designed and constructed to study the flow of such plugs at start up operations. Experiments have been performed using model fluid and model hydrate particles. The propagations of initial plugs in a bend were recorded with impedance probes along the pipe. The experimental results show a dispersion of the plug front. A peak in pressure drop was also recorded when the plugs were passing the bend. The evolutions of the plugs have been simulated by numerical integration of the incompressible mass balance equations, with an imposed mixture velocity. The slip between particles and carrier fluid has been calculated using a drag relation together with a particle-fluid force balance.
Abstract: Moisture is an important consideration in many
aspects ranging from irrigation, soil chemistry, golf course, corrosion
and erosion, road conditions, weather predictions, livestock feed
moisture levels, water seepage etc. Vegetation and crops always
depend more on the moisture available at the root level than on
precipitation occurrence. In this paper, design of an instrument is
discussed which tells about the variation in the moisture contents of
soil. This is done by measuring the amount of water content in soil by
finding the variation in capacitance of soil with the help of a
capacitive sensor. The greatest advantage of soil moisture sensor is
reduced water consumption. The sensor is also be used to set lower
and upper threshold to maintain optimum soil moisture saturation and
minimize water wilting, contributes to deeper plant root growth
,reduced soil run off /leaching and less favorable condition for insects
and fungal diseases. Capacitance method is preferred because, it
provides absolute amount of water content and also measures water
content at any depth.
Abstract: In this paper, the requirement for Coke quality
prediction, its role in Blast furnaces, and the model output is
explained. By applying method of Artificial Neural Networking
(ANN) using back propagation (BP) algorithm, prediction model has
been developed to predict CSR. Important blast furnace functions
such as permeability, heat exchanging, melting, and reducing
capacity are mostly connected to coke quality. Coke quality is further
dependent upon coal characterization and coke making process
parameters. The ANN model developed is a useful tool for process
experts to adjust the control parameters in case of coke quality
deviations. The model also makes it possible to predict CSR for new
coal blends which are yet to be used in Coke Plant. Input data to the
model was structured into 3 modules, for tenure of past 2 years and
the incremental models thus developed assists in identifying the
group causing the deviation of CSR.
Abstract: Compacted clay liners (CCLs) are the main materials
used in waste disposal landfills due to their low permeability. In this
study, the effect on the shear resistant of clays with inorganic salt
solutions as permeate fluid was experimentally investigated. For this
purpose, NaCl inorganic salt solution at concentrations of 2, 5, 10%
and deionized water were used. Laboratory direct shear and Vane
shear tests were conducted on three compacted clays with low,
medium and high plasticity. Results indicated that the solutions type
and its concentration affect the shear properties of the mixture. In the
light of this study, the influence magnitude of these inorganic salts in
varies concentrations in different clays were determined and more
suitable compacted clay with the compare of plasticity were found.
Abstract: Bluetooth is a personal wireless communication
technology and is being applied in many scenarios. It is an emerging
standard for short range, low cost, low power wireless access
technology. Current existing MAC (Medium Access Control)
scheduling schemes only provide best-effort service for all masterslave
connections. It is very challenging to provide QoS (Quality of
Service) support for different connections due to the feature of
Master Driven TDD (Time Division Duplex). However, there is no
solution available to support both delay and bandwidth guarantees
required by real time applications. This paper addresses the issue of
how to enhance QoS support in a Bluetooth piconet. The Bluetooth
specification proposes a Round Robin scheduler as possible solution
for scheduling the transmissions in a Bluetooth Piconet. We propose
an algorithm which will reduce the bandwidth waste and enhance the
efficiency of network. We define token counters to estimate traffic of
real-time slaves. To increase bandwidth utilization, a back-off
mechanism is then presented for best-effort slaves to decrease the
frequency of polling idle slaves. Simulation results demonstrate that
our scheme achieves better performance over the Round Robin
scheduling.
Abstract: Lanthanum oxide is to be recovered from monazite,
which contains about 13.44% lanthanum oxide. The principal
objective of this study is to be able to extract lanthanum oxide from
monazite of Moemeik Myitsone Area. The treatment of monazite in
this study involves three main steps; extraction of lanthanum
hydroxide from monazite by using caustic soda, digestion with nitric
acid and precipitation with ammonium hydroxide and calcination of
lanthanum oxalate to lanthanum oxide.
Abstract: In this paper, the signal transmission analysis of the
semicircle-shaped via structure for the differential pairs is presented in
the frequency range up to 10 GHz. In order to improve the signal
transmission properties in the differential pairs, single via is separated
centrally into two semicircle-shaped sections, which are
interconnected with the traces of differential pairs respectively. This
via structure make possible to route differential pairs using only one
via. In addition, it can improve impedance discontinuity around its
region and then enhance the signal transmission properties in the
differential pairs. The electrical analysis such as S-parameter
calculation and eye diagram simulation has been performed to
investigate the improvement of the signal transmission property in the
differential pairs with new via structure.
Abstract: Validation of an automation system is an important issue. The goal is to check if the system under investigation, modeled by a Petri net, never enters the undesired states. Usually, tools dedicated to Petri nets such as DESIGN/CPN are used to make reachability analysis. The biggest problem with this approach is that it is impossible to generate the full occurence graph of the system because it is too large. In this paper, we show how computational methods such as temporal logic model checking and Groebner bases can be used to verify the correctness of the design of an automation system. We report our experimental results with two automation systems: the Automated Guided Vehicle (AGV) system and the traffic light system. Validation of these two systems ranged from 10 to 30 seconds on a PC depending on the optimizing parameters.
Abstract: Random Forests are a powerful classification technique, consisting of a collection of decision trees. One useful feature of Random Forests is the ability to determine the importance of each variable in predicting the outcome. This is done by permuting each variable and computing the change in prediction accuracy before and after the permutation. This variable importance calculation is similar to a one-factor-at a time experiment and therefore is inefficient. In this paper, we use a regular fractional factorial design to determine which variables to permute. Based on the results of the trials in the experiment, we calculate the individual importance of the variables, with improved precision over the standard method. The method is illustrated with a study of student attrition at Monash University.
Abstract: In this paper, we present a novel approach to location
system under indoor environment. The key idea of our work is
accurate distance estimation with cricket-based location system using
A* algorithm. We also use magnetic sensor for detecting obstacles in
indoor environment. Finally, we suggest how this system can be used
in various applications such as asset tracking and monitoring.