Regression Error Characteristic Optimisation of Non-Linear Models.

Copyright © 2006 Springer-Verlag Berlin Heidelberg. The final publication is available at link.springer.comBook title: Multi-Objective Machine LearningIn this chapter recent research in the area of multi-objective optimisation of regression models is presented and combined. Evolutionary multi-objective optimisation techniques are described for training a population of regression models to optimise the recently defined Regression Error Characteristic Curves (REC). A method which meaningfully compares across regressors and against benchmark models (i.e. ‘random walk’ and maximum a posteriori approaches) for varying error rates. Through bootstrapping training data, degrees of confident out-performance are also highlighted

Experimental analysis of bound handling techniques in particle swarm optimization

Many practical optimization problems are constrained, and have a bounded search space. In this paper, we propose and compare a wide variety of bound handling techniques for particle swarm optimization. By examining their performance on flat landscapes, we show that many bound handling techniques introduce significant search bias. Furthermore, we compare the performance of many bound handling techniques on a variety of test problems, demonstrating that the bound handling technique can have a major impact on the algorithm performance, and that the method recently proposed as standard does generally not perform well

The Undergraduate Library (Book Review)

published or submitted for publicatio

A retrospective epidemiologic study to define risk factors, microbiology, and clinical outcomes of infective endocarditis in a large tertiary-care teaching hospital

Objective: This study aims to define risk factors as well as their association with microbiology and clinical outcomes in a large US infective endocarditis population. Methods: Hospital records were searched for appropriate infective endocarditis–related ICD codes from 16 July 2007 to 13 August 2015. A total of 363 cases were retrospectively identified that met definite Modified Duke Criteria for infective endocarditis and were analyzed by age group, causative organism, and associated risk factors for use of valvular surgical intervention, 30/90/180-day mortality after admission, and embolic phenomena. Results: Chronic hemodialysis was the most common risk factor (26.7% of cases). Of all age groups, those aged 78+ years had the lowest 30-day mortality but those aged 58–77 years had the highest mortality (p = 0.039). Staphylococcus aureus was the most prevalent causative organism. Those aged 78–97 years were more likely to have enterococcal infective endocarditis than those aged 18–27 years (p = 0.0144). Chronic hemodialysis associated infective endocarditis was more likely to be caused by coagulase-negative staphylococcus (p = 0.0121) and have a higher 30-day mortality (p = 0.141) than intravenous drug use associated infective endocarditis. Intravenous drug use and chronic hemodialysis were similarly likely to be caused by S. aureus . Intravenous drug use associated infective endocarditis was more likely to be caused by viridans group streptococci (p = 0.0001). Fungal infective endocarditis was most likely to embolize. Chronic hemodialysis patients were less likely to undergo valvular surgery (p = 0.001) and those with chronic hemodialysis who did had lower mortality than those only managed medically that did not reach statistical significance (p = 0.2991). Infective endocarditis caused by coagulase-negative staphylococci had the greatest 30-day mortality at 31.3% but did not reach statistical significance over all other causative organisms (p = 0.060). Conclusion: In our infective endocarditis population, S. aureus is the predominant causative organism. Chronic hemodialysis is the most common risk factor present in infective endocarditis populations and has greater association with coagulase-negative staphylococci and 30-day mortality. Intravenous drug use had the lowest mortality among risk factors with a similar proportion of S. aureus infective endocarditis compared to chronic hemodialysis but a higher proportion of viridans group streptococci infective endocarditis cases. Further study will need to be performed on prevention and treatment of infective endocarditis in chronic hemodialysis patients

Improving PSO-based multi-objective optimization using crowding, mutation and � -dominance

Abstract. In this paper, we propose a new Multi-Objective Particle Swarm Optimizer, which is based on Pareto dominance and the use of a crowding factor to filter out the list of available leaders. We also propose the use of different mutation (or turbulence) operators which act on different subdivisions of the swarm. Finally, the proposed approach also incorporates the ¡-dominance concept to fix the size of the set of final solutions produced by the algorithm. Our approach is compared against five state-of-the-art algorithms, including three PSO-based approaches recently proposed. The results indicate that the proposed approach is highly competitive, being able to approximate the front even in cases where all the other PSO-based approaches fail.

Improving the prescribing of palivizumab

© 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians) Aim: Palivizumab prevents respiratory syncytial virus (RSV) in children at high risk of severe disease. This paper reviews the use and effectiveness of palivizumab at two tertiary paediatric hospitals (hospitals A and B) in New South Wales, Australia. Methods: Children prescribed palivizumab during the pre-intervention period, 1 January 2013 until 31 December 2014, were compared with children under 2 years of age who were admitted to paediatric intensive care units (PICUs) with an RSV infection. Eligibility for palivizumab was determined. To improve evidence-based utilisation of palivizumab, a ‘streamlined palivizumab individual patient use’ (IPU) pro forma was introduced at hospital A during 2015, and its applicability was reviewed. Results: In the 2 years prior to implementing the streamlined IPU, 47 children received palivizumab, with 87% at hospital A. Of the children at hospital A, 32% did not meet the guidelines, and 32% did not complete the course. While 13% of children admitted to PICU for RSV infection were eligible for palivizumab, none received it prior to admission. In 2015, 16 streamlined IPUs were submitted, and 11 patients received palivizumab. Of these patients, 27% did not meet the guidelines, and 63% did not complete the course. Of the children who received palivizumab during the three RSV seasons, one developed an RSV infection, and none were admitted to PICU. Conclusions: Palivizumab is often prescribed without meeting recognised best practice guidelines, and patients eligible are frequently not prescribed palivizumab. The streamlined IPU, implemented in hospital A, excluded patients who did not meet guidelines. The pro forma needs further refinement, and complementary strategies introduced to improve compliance