52,147 research outputs found

    Kelly Criterion revisited: optimal bets

    Full text link
    Kelly criterion, that maximizes the expectation value of the logarithm of wealth for bookmaker bets, gives an advantage over different class of strategies. We use projective symmetries for a explanation of this fact. Kelly's approach allows for an interesting financial interpretation of the Boltzmann/Shannon entropy. A "no-go" hypothesis for big investors is suggested.Comment: APFA5 Conference, Torino, 200

    Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures

    Get PDF
    Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong blade–vortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor

    Arlis/ANZ 2.0

    Get PDF
    We've all been hearing about Web 2.0 and Library 2.0 lately. But just what are they all about, and is there anything there that Arlis/ANZ can take advantage of in order to better go about its business? Can there, should there, be an Arlis/ANZ 2.0? Arlis/ANZ, the Arts Libraries Society of Australia and New Zealand, is preparing to review it's online prescence. The Arlis/ANZ website is now three years old, and has been well maintained during that time. However it has not yet been systematically reviewed in terms of content, functionality, and strategic direction. The Arlis/ANZ Website version 'One' will be redeveloped into Arlis/ANZ Website version 'Two'. Although much of that review will concentrate on the structure, look and feel of the site, the review process offers an opportunity to incorporate Web 2.0 developments. By incorporating that 'best' of Web 2.0 in a strategic manner, Arlis/ANZ 2.0 - the website - has powerful potential to contribute toward the strength, cohesion and ongoing development of Arlis/ANZ 2.0 - the Society

    Space shuttle orbiter leading-edge flight performance compared to design goals

    Get PDF
    Thermo-structural performance of the Space Shuttle orbiter Columbia's leading-edge structural subsystem for the first five (5) flights is compared with the design goals. Lessons learned from thse initial flights of the first reusable manned spacecraft are discussed in order to assess design maturity, deficiencies, and modifications required to rectify the design deficiencies. Flight data and post-flight inspections support the conclusion that the leading-edge structural subsystem hardware performance was outstanding for the initial five (5) flights

    Injury in Ireland

    Get PDF
    Injury mortality is the fourth commonest cause of death in Ireland. The treatment of injuries has a major impact on our hospitals and on our budget for health. Long term disability following accidents is a serious problem. The aim of this report is to examine the impact of accidents and injuries on the Irish population by analysing routine mortality and morbidity data, and to identify in turn those areas where preventive measures could have an impact. In Section One the literature review details the advantages and disadvantages of each type of routine data source used in this report. The interpretation of data should take account of the constraints of the available data collected. The usefulness of routine data collection is highlighted, while identifying areas for improvement. In Section Two the methodology employed in the study is detailed. In Section Three data on hospital admissions over a five-year period 1993-1997 are presented. An overview of injury admissions is presented, followed by further analysis of injury data by both cause and by age group. In Section Four data on all accident-related deaths over a 17-year period, 1980-1996, are presented, with overall mortality data and mortality data by age group and by major causes of injury death detailed. In Section Five comparisons are made between the eight health board regions for rates of admissions and deaths due to injury. In presenting the data we use a matrix format devised and recommended by the International Collaborative Effort on Injury Statistics to display injury simultaneously by cause and intent. The use of a common format will also facilitate regional and international comparisons. In Section Six the priority recommendations for injury prevention are outlined. The key findings are then discussed and further recommendations are presented with the aim of injury prevention, reduction of disability and improvement in injury surveillance

    X-ray CT analysis after blast of composite sandwich panels

    Get PDF
    Four composite sandwich panels with either single density or graded density foam cores and different face-sheet materials were subjected to full-scale underwater blast testing. The panels were subjected to 1kg PE4 charge at a stand-off distance of 1 m. The panel with graded density core and carbon fiber face-sheets had the lowest deflection. Post-blast damage assessment was carried out using X-ray CT scanning. The damage assessment revealed that there is a trade-off between reduced panel deflection and panel damage. This research has been performed as part of a program sponsored by the Office of Naval Research (ONR)

    First Record of \u3ci\u3eOchlerotatus Japonicus\u3c/i\u3e (Diptera: Culicidae) in St. Joseph County, Indiana

    Get PDF
    A single female specimen of Ochlerotatus japonicus (Theobald)(formerly Aedes japonicus), the Asian bush mosquito, was captured in St. Joseph County, IN on 29 July 2004. This is the first report of that species in northern Indiana. Additional specimens were subsequently collected, indicating probable establishment throughout the county

    Contemporary results from the PelvEx collaborative:improvements in surgical outcomes for locally advanced and recurrent rectal cancer

    Get PDF
    Aim: The PelvEx Collaborative collates global data on outcomes following exenterative surgery for locally advanced and locally recurrent rectal cancer (LARC and LRRC, respectively). The aim of this study is to report contemporary data from within the collaborative and benchmark it against previous PelvEx publications. Method: Anonymized data from 45 units that performed pelvic exenteration for LARC or LRRC between 2017 and 2021 were reviewed. The primary endpoints were surgical outcomes, including resection margin status, radicality of surgery, rates of reconstruction and associated morbidity and/or mortality. Results: Of 2186 patients who underwent an exenteration for either LARC or LRRC, 1386 (63.4%) had LARC and 800 (36.6%) had LRRC. The proportion of males to females was 1232:954. Median age was 62 years (interquartile range 52–71 years) compared with a median age of 63 in both historical LARC and LRRC cohorts. Compared with the original reported PelvEx data (2004–2014), there has been an increase in negative margin (R0) rates from 79.8% to 84.8% and from 55.4% to 71.7% in the LARC and LRRC cohorts, respectively. Bone resection and flap reconstruction rates have increased accordingly in both cohorts (8.2%–19.6% and 22.6%–32% for LARC and 20.3%–41.9% and 17.4%–32.1% in LRRC, respectively). Despite this, major morbidity has not increased. Conclusion: In the modern era, patients undergoing pelvic exenteration for advanced rectal cancer are undergoing more radical surgery and are more likely to achieve a negative resection margin (R0) with no increase in major morbidity.</p
    corecore