Fay, Damien; Ringwood, John; Condon, Marissa; Kelly, Michael

Abstract:

The paper investigates whether a time series or a set of independent points is a more appropriate description of 24-hour Irish electrical load data. A set of independent points means that the load at each hour of the day is independent from the load at any other hour. The data is first split into 24 series, one for each hour of the day i.e. a 1am 2am 3am series etc. These are called parallel series. The linear cross-correlation's of the parallel series are used to indicate independence. While the loads at 9am and 6pm to 8pm appear independent the remaining loads are highly inter-correlated. This suggests that 24-hour electrical load data has a dual nature. Two techniques are used to test this hypothesis. The first technique models each parallel series using neural networks. This technique is found to be computationally expensive. The second technique uses a hybrid technique called the Multi Time Scale (MTS) technique. This models 24-hour electrical load data as a time series th...

Regression using Gaussian process models is applied to time-series data analysis. To extract from the data separate components with different frequency scales, the Gaussian regression methodology is extended through the use of multiple Gaussian process models. Fast and memory-efficient methods, as required by Gaussian regression to cater for large time-series data sets, are discussed. These
methods are based on the generalised Schur algorithm and a procedure to determine the Schur decomposition of matrices, the key step to realising them, is presented. In
addition, a procedure to appropriately initialise the Gaussian process model training is presented. The utility of the procedures is illustrated by application of a multiple Gaussian process model to extract separate components with different frequency scales from a 5000-point time-series data set with gaps.

Chesi, D.; Colaneri, P.; Geromel, J.C.; Middleton, R.; Shorten, Robert N.

Abstract:

This paper investigates the minimum dwell time
for switched linear systems. It is shown that a sequence of
upper bounds of the minimum dwell time can be computed
by exploiting homogeneous polynomial Lyapunov functions
and convex optimization problems based on linear matrix
inequalities (LMIs). This sequence is obtained by adopting
two possible representations of homogeneous polynomials, one
based on Kronecker products, and the other on the square
matrix representation (SMR). Some examples illustrate the
use and the potentialities of the proposed approach. It is also
conjectured that the proposed approach is asymptotically nonconservative,
i.e. the exact minimum dwell time is obtained by
using homogeneous polynomials with sufficiently large degree.

This paper describes the application of a multi-time-scale
technique to the modelling and forecasting of short-term
electrical load. The multi-time-scale technique is based on
adjusting the underlying short sampling period forecast time
series with specific target points and possible aggregated
demand. This allows not only improvement of the short
sampling period forecast, but also focuses on weighting the
accuracy of the forecast at certain critical points e.g. the
overnight minimum and daily peaks. Various model types may be utilised at the upper level (forecating the aggregated
consumption and target points at daily level), including
intelligent models such as neural and fuzzy models, but the
base model is currently restricted to a linear form. Results
for the Irish national electrical grid demonstrate the
effectiveness of the technique.

The focus of the research is circle time, a widely used method in Irish primary schools. It involves children sitting in a circle with their teacher using method-specific techniques and strategies to promote self-esteem, develop skills and support positive classroom relationships. The theoretical and conceptual framework adopted has empowerment of children as its central focus, and is supported by theories of self-esteem, emotional intelligence, and voice and participation theory. Learning and counselling theories also inform the research.
The rise of circle time historically is documented against a backdrop of curricular and social changes in Ireland. These include a psychological turn in educational and societal discourse, a move towards inclusive and rights-based education, and an orientation towards personal development evident in recent reviews of the SPHE Curriculum (1999). The current research is prompted and informed by a review of research on circle time which suggests that...

Automatic Vehicle Location (AVL) systems are increasingly being used by transit agencies for the real time monitoring of their vehicles. AVL systems can be used to improve the service given to passengers by using informat8ion on the current position of buses to maintain headways or increase reliability by improved operational control and provide an estimate of as to the arrival time of the next bus at the stop. In real-time bus tracking systems, some positional uncertainty is usually associated with eh location of buses in service that are tracked using a locational device such as a Global Positioning System (GPS) receiver. Rather than raw coordinates, the location is usually better understood in terms of the landmarks along the route, particularly the named stop. Three prediction models have been implemented to estimate the location of vehicles on bus routes. Analysis indicates that one based on mining historical data for patterns gives more accurate results than regression an...

Time domain control of wave energy converters
requires knowledge of future incident wave elevation in order to
approach conditions for optimal energy extraction. Autoregressive
models revealed to be a promising approach to the prediction
of future values of the wave elevation only from its past history.
Results on real wave observations from different ocean locations
show that AR models allow to achieve very good predictions
for more than one wave period in the future if the focus is put
on low frequency components, which are the most interesting
from a wave energy point of view. For real-time implementation,
however, the lowpass filtering introduces an error in the wave
time series, as well as a delay, and AR models need to be designed
so to be as robust as possible to these errors.

Lowry, John P.; Griffin, Karen; McHugh, Stephen B.; Lowe, Andrew S.; Tricklebank, Mark; Sibson, Nicola R.

Abstract:

Long-term in-vivo electrochemistry (LIVE) enables real-time monitoring and measurement of brain
metabolites. In this study we have simultaneously obtained blood oxygenation level dependent (BOLD)
fMRI and amperometric tissue O2 data from rat cerebral cortex, during both increases and decreases in
inspired O2 content. BOLD and tissue O2 measurements demonstrated close correlation (r=0.7898) during
complete (0%) O2 removal, with marked negative responses occurring ca. 30 s after the onset of O2 removal.
Conversely, when the inspired O2 was increased (50, 70 and 100% O2 for 1 min) similar positive rapid
changes (ca. 15 s) in both the BOLD and tissue O2 signals were observed. These findings demonstrate, for the
first time, the practical feasibility of obtaining real-time metabolite information during fMRI acquisition, and
that tissue O2 concentration monitored using an O2 sensor can serve as an index of changes in the magnitude
of the BOLD response. As LIVE O2 sensors can be used in awa...

Glover, John C.; Lazzarini, Victor; Timoney, Joseph

Abstract:

Real-time musical note onset detection plays a vital role in many audio
analysis processes, such as score following, beat detection and various sound
synthesis by analysis methods. This paper provides a review of some of the
most commonly used techniques for real-time onset detection. We suggest
ways to improve these techniques by incorporating linear prediction, as well
as presenting a novel algorithm for real-time onset detection using sinusoidal
modelling. We provide comprehensive results for both the detection accuracy
and the computational performance of all of the described techniques,
evaluated using Modal, our new open source library for musical onset detection,
which comes with a free database of samples with hand-labelled note
onsets.

Pekonen, Jussi; Lazzarini, Victor; Timoney, Joseph; Kleimola, Jari; Valimaki, Vesa

Abstract:

Discrete-time modelling strategies of analogue Moog sawtooth oscillator waveforms are presented. Two alternative approaches
suitable for real-time implementation are proposed, one modelling the analogue waveform in time domain using phase distortion
synthesis and another matching the spectrum of an existing antialiasing sawtooth oscillator to the corresponding analogue
spectrum using a first-order IIR post-equalising filter. A parameter estimation procedure for both approaches is explained and
performed. Performance evaluation using polynomial fits for the estimated parameters is carried out, and good matches between
the model outputs and recorded waveforms are obtained. The best match of the tested algorithms is produced by the phase
distortion model and by post-equalising the fourth-order B-spline bandlimited step function sawtooth oscillator.

One of the most common issues in wireless networks is the problem of increasing the network capacity by alleviating or eliminating collisions with the minimum possible cost. The combination of time division protocols together with efficient slot allocation mechanisms is an effective way to achieve scalability and provide high reliability. In this paper, I describe the parameters that must be taken into account when designing LoRa(WAN)-based time-slotted protocols. I show that the LoRaWAN case differs from any other synchronous wireless solution mainly due to the characteristics of the LoRa physical layer and the regional radio duty cycle restrictions. I also propose a frame structure which has been adopted during the implementation of a time-slotted LoRa approach.

Charlton, Martin; Brunsdon, Chris; Cahalane, Conor; Pforte, Lars

Abstract:

A challenging problem exists in the estimation of missing space-time data where the time series are
relatively short, and the space series belong to a spatial hierarchy. An example is provided by the
population estimates for regions belonging to the NUTS hierarchy which are available from the
EUROSTAT data portal. The table demo_r_gind3 provides estimates of the population of
NUTS0/1/2/3 regions at the 1st January 2000…2012 inclusive. Inspection of the table reveals that
estimates are missing for 2000-2003 for two of the five NUTS3 regions in the NUTS2 region of
Liège. There are other instances of missing data at NUTS3 where there are data for the corresponding
higher level NUTS regions. The EUROSTAT table demo_r_d2jan provides estimates of the
population on the 1st January for a longer time period, 1990…2012 inclusive, but these are only to
NUTS2. Again, there is missing data. The question then arises as to whether it is possible to estimate
the missing series. The NUTS2 values act...

Behan, M.; Cahill, M.; Carry, M.; Clausen, G.; Dooley, V.; English, N.; Grainger, W.; O'Connor, David; O'Dwyer, Aidan; Ringwood, John

Abstract:

This paper discusses the estimation of process parameters and ti
me delay, in a Smith
predictor structure, using gradient algorithms in the time domain. A
number of estimation
algorithms are outlined and applied in simulation to the estimation of
the parameters of an
appropriate process model. An analytical exploration of the technique is also provided.

The function of this chapter is to examine Mahler’s philosophical
concept of time and the embodiment of this within the programmatic
and structural model of his six-movement Symphony no. 3. This
chapter shall argue that the composer’s newfound concept of time was
borne out of Friedrich Nietzsche’s fundamental doctrine in his book
Also Sprach Zarathustra1 (Thus Spoke Zarathustra) of 1885, from
which Mahler drew directly in the fourth movement of his third
symphony. It must be stated at this initial stage, however, that the
contextual significance of Nietzsche’s work extends far beyond the
borders of the fourth movement, instead radiating from this crucial
midpoint in both directions and acting as the central anchor from which
all contributory philosophical expressions in the symphony evolve. The
subject of Mahler’s concept and treatment of time with regard to
Nietzschean principals is but one of the ingredients exhibiting a
contextual and often disguised correlation between the liter...

Phase vecoder based approaches to audio time-scale modification introduce a reverberant artefact into the time scaled output. Recent techniques have been developed to reduce the presence of this artefact; however, these techniques have the effect of introducing additional issues relating to their application to multi-channel recordings. This paper addresses these issues by collectively analysing all channels prior to time-scaling each individual channel.

This paper uses an econometric analysis of the 1987 Economic and Social Research
Institute household survey data to assess the sources of the growth which has occurred in parttime
employment in the last decade. The models used allow both for the possibility that the
hours of work choice is a discrete one, and for the influence of the demand side of the labour
market on a woman's choice between part-time and full-time work. The results confirm the
impression gained from descriptive statistics that the growth in part-time employment has been
supply-led, but that the growth of the Services sector has facilitated this increase.

In an isopotential neuron with rapid response, it has been shown that the receptive fields formed by Hebbian synaptic modulation depend on the principal eigenspace of Q(0), the input autocorrelation matrix, where Qij(τ) = 〈ξi(τ) ξj(t − T)〉 and ξi(t) is the input to synapse i at time t (Oja 1982). We relax the assumption of isopotentiality, introduce a time-skewed Hebb rule, and find that the dynamics of synaptic evolution are determined by the principal eigenspace of . This matrix is defined by , where Kij(τ) is the neuron's voltage response to a unit current injection at synapse j as measured τ seconds later at synapse i, and ψi(τ) is the time course of the opportunity for modulation of synapse i following the arrival of a presynaptic action potential.

In this work we present the time dependent dielectric breakdown (TDDB) characteristics of LaO capped HfO2 layers with an equivalent oxide thickness of 8Å. The layers show maximum operating voltages in excess of 1V. Such high reliability can be attributed to very high Weibull slopes. We examine the origin of the high slopes by a detailed study of the evolution of the stress induced leakage current with time, temperature and stress voltage.

Assembly line balancing (ALB) is a well-known combinatorial optimization problem in production and operations management area. Due to the NP-hard nature of the ALB problem, many attempts have been made to solve the problem efficiently. In this study, biologically inspired evolutionary computing tool which is genetic algorithm (GA) is adopted to solve the ALB problem with the objective of minimizing the idle time in the workstation. The key issue in solving ALB is how to generate a feasible task sequence which does not violate the precedence constraints. This task sequencing is a vital work to be solved prior assigning tasks to workstation. In order to generate only feasible solution, a repairing strategy based topological sort is integrated in the GA procedure. The ALB test problems benchmarked from the literature are used in the study and the computational results show that the proposed approach is capable to obtain feasible solution with minimum idle time for a simple model assemb...

Clarke, Siobhan F.; Murphy, Eileen F.; O'Sullivan, Orla; Ross, R. Paul; O'Toole, Paul W.; Shanahan, Fergus; Cotter, Paul D.

Abstract:

Links between the gut microbiota and host metabolism have provided new perspectives on obesity. We previously showed that the link between the microbiota and fat deposition is age- and time-dependent subject to microbial adaptation to diet over time. We also demonstrated reduced weight gain in diet-induced obese (DIO) mice through manipulation of the gut microbiota with vancomycin or with the bacteriocin-producing probiotic Lactobacillus salivarius UCC118 (Bac+), with metabolic improvement achieved in DIO mice in receipt of vancomycin. However, two phases of weight gain were observed with effects most marked early in the intervention phase. Here, we compare the gut microbial populations at the early relative to the late stages of intervention using a high throughput sequencing-based analysis to understand the temporal relationship between the gut microbiota and obesity. This reveals several differences in microbiota composition over the intervening period. Vancomycin dramatically al...

A residual gas analyser is an instrument which, by
ionising the ambient gas under low pressure (<10” atm),
enumerates the different atomic elements in the gas and
measures their relative abundance. The analysis of the
gas is done using a mass spectrometer, which identifies
the atomic elements by separating the atoms, group of
atoms or molecules according to their mass to charge
ratio. Mass spectrometers are classified on the basis of
how the atomic mass separation is accomplished. In a
time-of-flight mass spectrometer the mass separation is
achieved by injecting a mono-energetic ion beam, into a
long electric/magnetic field free tube. The time taken to
reach the end of the tube depends on the square root of
the ions mass to charge ratio and so by observing the
output times of whatever ions are present, the different
atomic elements are revealed. The relative abundance of
the elements is simply the ratio of the number of ions
egressing the tube at the specific times.
This thesis ...

Killard, Anthony J.; Micheli, Laura; Grennan, Kathleen; Franek, Milan; Kolar, Vladimir; Moscone, Danila; Palchetti, Ilaria; Smyth, Malcolm R.

Abstract:

Immunoanalytical techniques have found widespread use due to the characteristics of specificity and wide applicability for many analytes, from large polymer antigens, to simple haptens, and even single atoms. Electrochemical sensors offer benefits of technical simplicity, speed and convenience via direct transduction to electronic equipment. Together, these two systems
offer the possibility of a convenient, ubiquitous assay technique with high selectivity. However, they are still not widely used, mainly due to the complexity of the associated immunoassay methodologies. A separation-free immunoanalytical technique is described here, which has allowed for the analysis of atrazine in real time and in both quasi-equilibrium and stirred batch configurations. It illustrated that determinations as low as 0.13mM (28 ppb) could be made using equilibrium incubation with an analytical range of 0.1–10mM. Measurements could be made between 1 and 10 mM within several minutes using a real-time, st...

In this paper, we present a series of experiments that were conducted to determine how using adaptive
levels of artistic abstraction within an interactive 3D scene can influence user gaze behaviour. We found that
when an object was placed in the center of stylised focus, users took significantly less time to complete a search
and recognition task in comparison to normal renderings or when the target object was heavily abstracted i.e.
stylistically out-of-focus. We also compared a number of different abstraction techniques and found that some
abstraction styles consistently lead to faster search times than others. Finally we performed experiments using
an eye-tracker to show that our real-time abstraction techniques can successfully draw user attention to specific
objects within an interactive scene. We believe that our experimental framework will be useful in the future for
comparing the effectiveness of different NPR styles in influencing a user?s perception of a scene.

Achieving predictable communication latency in an ad
hoc IEEE 802.11 wireless local area network necessitates
an approach that overcomes the impact of the underlying
non-deterministic contention-based medium access control
(MAC) protocol. In this paper, we assess the feasibility of
using a Time Division Multiple Access (TDMA) layer above
the IEEE 802.11 MAC protocol in order to achieve such
predictable communication latency.
We present the design and implementation of this TDMA
layer and describe the influence of both the characteristics
of the IEEE 802.11MAC protocol and of the dynamics of an
ad hoc network on its design. We show that our approach
can yield the predictability and stability required to support
real-time communication in a real ad hoc environment,
typified by dynamic host mobility and varied offered load,
subject to identified constraints.

This work constitutes an attempt to estimate time preference factors in a direct way from survey data, without relying on consumption data and on particular estimation techniques. By using microeconomic data obtained from the Bank of Italy Survey of Household Income and Wealth (for the year 2000) and a simple second order Taylor expansion of a generic utility function we will compute, for each agent, a utility discount factor. The interesting features of the dataset will also enable us to relate discount factors to a large number of social, economic, and demographic variables. Agents do appear to discount future utility flows at rates which vary across age, education, civil status, income and wealth situations; more importantly, it is suggested that risk and market incompleteness should be considered as important determinants of time preference parameters.