1,406 research outputs found
Approaches for multi-step density forecasts with application to aggregated wind power
The generation of multi-step density forecasts for non-Gaussian data mostly
relies on Monte Carlo simulations which are computationally intensive. Using
aggregated wind power in Ireland, we study two approaches of multi-step density
forecasts which can be obtained from simple iterations so that intensive
computations are avoided. In the first approach, we apply a logistic
transformation to normalize the data approximately and describe the transformed
data using ARIMA--GARCH models so that multi-step forecasts can be iterated
easily. In the second approach, we describe the forecast densities by truncated
normal distributions which are governed by two parameters, namely, the
conditional mean and conditional variance. We apply exponential smoothing
methods to forecast the two parameters simultaneously. Since the underlying
model of exponential smoothing is Gaussian, we are able to obtain multi-step
forecasts of the parameters by simple iterations and thus generate forecast
densities as truncated normal distributions. We generate forecasts for wind
power from 15 minutes to 24 hours ahead. Results show that the first approach
generates superior forecasts and slightly outperforms the second approach under
various proper scores. Nevertheless, the second approach is computationally
more efficient and gives more robust results under different lengths of
training data. It also provides an attractive alternative approach since one is
allowed to choose a particular parametric density for the forecasts, and is
valuable when there are no obvious transformations to normalize the data.Comment: Corrected version includes updated equation (18). Published in at
http://dx.doi.org/10.1214/09-AOAS320 the Annals of Applied Statistics
(http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics
(http://www.imstat.org
Open-source software for generating electrocardiogram signals
ECGSYN, a dynamical model that faithfully reproduces the main features of the
human electrocardiogram (ECG), including heart rate variability, RR intervals
and QT intervals is presented. Details of the underlying algorithm and an
open-source software implementation in Matlab, C and Java are described. An
example of how this model will facilitate comparisons of signal processing
techniques is provided.Comment: 10 pages, 5 figure
Schooled Bodies? - Adolescents Encountering Complexities in the Pursuit of Embodied Validation
This research is concerned with adolescence as an embodied experience. It
represents an attempt to bridge the gap between the sociology o f childhood and the
sociology o f the body, a connection that is infrequently made within sociological
literature.
This investigation is specifically concerned with questioning how
adolescents are schooled on the body and if the types o f schooling they receive
give rise to complexities in their pursuit o f embodied validation. Throughout this
study I explore how adolescents are schooled on the body in many social spheres.
From the ever-abounding, ever-astounding body images portrayed in consumer
culture; to the hushed comments directed at the bodies o f school peers. From the
popularity o f those with the physical prowess to make it onto prestigious school
teams; to the physical regulation adopted by mothers and fathers. Each o f the
aforementioned contexts, among others school adolescents on the body to some
degree. However, this schooling may often be conflicting and contradictory,
leaving adolescents to overcome the complexities they encounter.
It is a primary contention o f this research that adolescents are not passively
schooled on the body to such a degree that they become slaves to contemporary
trends. This study shows how youths actively negotiate the forms o f embodiment
they encounter and the complexities they experience with certain forms of
embodiment. This research provides a vital window into the worlds of
participating youths and importantly how they experience these worlds as
embodied individuals
Review of "System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal
"System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal introduces the relevant concepts, terminology, and techniques of this field of science. It emphasises the modelling and computational challenges of taking a multidisciplinary approach to biology. This book provides a comprehensive introduction to systems biology and will form a valuable resource for students, teachers and researchers from both experimental and theoretical disciplines
Randomised controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series
OBJECTIVE: To test the hypothesis that homoeopathy is a placebo by examining its effect in patients with allergic rhinitis and so contest the evidence from three previous trials in this series.
Design: Randomised, double blind, placebo controlled, parallel group, multicentre study.
SETTING: Four general practices and a hospital ear, nose, and throat outpatient department.
PARTICIPANTS: 51 patients with perennial allergic rhinitis. Intervention: Random assignment to an oral 30c homoeopathic preparation of principal inhalant allergen or to placebo.
MAIN OUTCOME MEASURES: Changes from baseline in nasal inspiratory peak flow and symptom visual analogue scale score over third and fourth weeks after randomisation.
RESULTS: Fifty patients completed the study. The homoeopathy group had a significant objective improvement in nasal airflow compared with the placebo group (mean difference 19.8 l/min, 95% confidence interval 10.4 to 29.1, P=0.0001). Both groups reported improvement in symptoms, with patients taking homoeopathy reporting more improvement in all but one of the centres, which had more patients with aggravations. On average no significant difference between the groups was seen on visual analogue scale scores. Initial aggravations of rhinitis symptoms were more common with homoeopathy than placebo (7 (30%) v 2 (7%), P=0.04). Addition of these results to those of three previous trials (n=253) showed a mean symptom reduction on visual analogue scores of 28% (10.9 mm) for homoeopathy compared with 3% (1.1 mm) for placebo (95% confidence interval 4.2 to 15.4, P=0.0007).
CONCLUSION: The objective results reinforce earlier evidence that homoeopathic dilutions differ from placebo
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Improving Accuracy and Usability of Growth Charts: Case Study in Rwanda
Objectives We evaluate and compare manually collected paper records against electronic records for monitoring the weights of children under the age of 5. Setting Data were collected by 24 community health workers (CHWs) in 2 Rwandan communities, 1 urban and 1 rural. Participants The same CHWs collected paper and electronic records. Paper data contain weight and age for 320 boys and 380 girls. Electronic data contain weight and age for 922 girls and 886 boys. Electronic data were collected over 9 months; most of the data is cross-sectional, with about 330 children with time-series data. Both data sets are compared with the international standard provided by the WHO growth chart. Primary and secondary outcome measures The plan was to collect 2000 individual records for the electronic data set—we finally collected 1878 records. Paper data were collected by the same CHWs, but most data were fragmented and hard to read. We transcribed data only from children for whom we were able to obtain the date of birth, to determine the exact age at the time of measurement. Results Mean absolute error (MAE) and mean absolute percentage error (MAPE) provide a way to quantify the magnitude of the error in using a given model. Comparing a model, log(weight)=a+b log(age), shows that electronic records provide considerable improvements over paper records, with 40% reduction in both performance metrics. Electronic data improve performance over the WHO model by 10% in MAPE and 7% in MAE. Results are statistically significant using the Kolmogorov-Smirnov test at p\u3c0.01. Conclusions This study demonstrates that using modern electronic tools for health data collection is allowing better tracking of health indicators. We have demonstrated that electronic records facilitate development of a country-specific model that is more accurate than the international standard provided by the WHO growth chart
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An exploration of clinical teaching and learning within a preceptorship model in an acute care hospital in the Republic of Ireland
Preceptorship within clinical nurse teaching was introduced in Ireland in 2002. Little is known how this model has impacted upon the pedagogical practices of the preceptor or student learning in clinical practice. An international literature review highlighted the question of what constitutes effective teaching and learning in clinical practice which is the subject of this thesis.
An exploratory qualitative design was used to examine the clinical teaching and learning within the Irish preceptorship model. The sample comprised 13 students and 13 preceptors working together on four clinical areas in one hospital. Data were collected using semi- structured interviews and documentary analysis relating to the teaching and assessment of BNSc (general) students.
Main findings showed preceptors used strategies that fostered performance and understanding such as demonstration, coaching and scaffolding. Participants believed the key to effective learning was interactive dialogue and building the students' confidence within the confines of a consistent mutually respectful relationship where the preceptor had time to teach. Many variations in preceptors teaching practices were illuminated. Some preceptors' utilised teaching methods that had the potential to enhance problem solving and students' self-directed learning ability. However, many did not use or value these cognitive approaches. Yet all preceptors expected students to make appropriate judgements within the unpredictable environment of practice. The student role as learner in many preceptor- students' relationships was not well understood or valued. Some cases of good practice were elucidated where professional education was the focus of students learning. Conversely in many cases the findings suggest that the students' education was driven by service needs and values such as performance, team work and a work ethic. Other professional values such as patient empowerment and critical thinking were not a primary concern.
A best practice clinical teaching and learning model is offered based on the evidence of this study; recommendations as to its further modification and development are discussed. The research demonstrated how concepts such as cognitive apprenticeship (Coli ins 2006), situated teaching and learning in communities of practice (Lave 2009, Wenger 2009), and scaffolding (Vygotsky 1978) can be helpful in understanding the processes entailed in preceptorship. Therefore the research should provide both pragmatic guidance for nurse education in Ireland and more widely, and the development of our understanding about nurse education. The latter will add to the relatively weak theoretical underpinnings of much of the existing literature in nurse education research
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