419 research outputs found
Increasing Skin Infections and Staphylococcus aureus Complications in Children, England, 1997-2006
During 1997-2006, general practitioner consultations for skin conditions for children <18 years of age in England increased 19%, from 128.5 to 152.9/1,000 child-years, and antistaphylococcal drug prescription rates increased 64%, from 17.8 to 29.1/1,000 child-years. During the same time period, hospital admissions for Staphylococcus aureus infections rose 49% from 53.4 to 79.3/100,000 child-years.link_to_subscribed_fulltex
Testing the risk and return trade-off in the Athens stock exchange
The present thesis is focused on the examination of the relationship between specific variables with the application of asset pricing models as well as the employment of (G)ARCH models, unit root and cointegration analysis. A theoretical and empirical review on the models is presented and, more specifically, there is an empirical examination of the validity of the Capital Asset Pricing Model (CAPM) and the two main forms of the Arbitrage Pricing Theory (APT) in the Athens Stock Exchange (ASE) during the period 1989-2006. Furthermore, there is an empirical application of specific (G)ARCH models on the variables under examination and an investigation of whether there are long-run relationships between different sets of financial and macroeconomic variables – whether the variables are cointegrated.
The results of the tests show the inability of the CAPM to explain the behaviour of stocks for the period under examination, as well as for the sub-periods (1984-1994, 1995-2000, and 2001-2006 respectively). This means that the (optimal) market portfolio used in the CAPM presents a poor explanatory power on the returns of stocks. On the contrary, the results of the statistical APT model show that there may be factors other than the market portfolio that can explain the behaviour of stocks. Similarly, the results from the application of the macroeconomic APT model show that specific macroeconomic variables can partially explain stocks’ behaviour. Finally, the existence of long-run relationships between macroeconomic and financial variables, based on a series of cointegration tests, is evidence that there are different factors that can affect stocks, leading to a possible weak-form inefficiency of the Greek market
Dosing of oral penicillins in children: is big child=half an adult, small child=half a big child, baby=half a small child still the best we can do?
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Tensile performance of headed anchors in steel fiber reinforced and conventional concrete in uncracked and cracked state
Steel fiber reinforced concrete (SFRC) is currently the material of choice for a broad range of structural components. Through the use of SFRC, the entire, or a large portion of, conventional rebar reinforcement can be replaced, in order to improve the load-bearing behavior but also the serviceability and durability characteristics of engineering structures. The use of fiber reinforcement therefore plays a vital role in acute current and future construction industry objectives, these being a simultaneous increase in the service life of structures and the reduction of their environmental impact, in addition to resilience to extreme loads and environmental actions. Next to the extended use of SFRC, modern construction relies heavily on structural connections and assembly technologies, typically by use of bolt-type cast-in and post-installed concrete anchors. This paper addresses the influence of fiber reinforcement on the structural performance of such anchors in SFRC and, particularly, the load bearing behavior of single headed anchors under axial static loads in uncracked and cracked concrete. Along with a presentation of background information on previous studies of SFRC with a focus on anchor concrete breakout failure, the experimental investigations are described, and their results are presented and elaborated on by consideration of various research parameters. A comparison with current design approaches is also provided. The conclusions are deemed useful for structural engineering research and practice
Probabilistic studies on the shear strength of slender steel fiber reinforced concrete structures
Shear failure is a brittle and undesirable mode of failure in reinforced concrete structures. Many of the existing shear design equations for steel fiber reinforced concrete (SFRC) beams include significant uncertainty due to the failure in accurately predicting the true shear capacity. Given these, adequate quantification and description of model uncertainties considering the systematic variation in the model prediction and measured shear capacity is crucial for reliability-based investigation. Reliability analysis must account for model uncertainties in order to predict the probability of failure under prescribed limit states. This study focuses on the quantification and description of model uncertainty related to the current shear resistance predictive models for SFRC beams without shear reinforcement. The German (DAfStB) model displayed the lowest bias and dispersion, whereas the fib Model 2010 and the Bernat et al., model displayed the highest bias and dispersion. The inconsistencies observed in the resistance model uncertainties at the variation of shear span to effective depth ratio are a major cause for concern, and differentiation with respect to this parameter is advised. Finally, in line with the EN 1990 semi-probabilistic approach for reliability-based design, the global partial safety factors related to model uncertainties in the shear resistance prediction of SFRC beams are proposed
Intraclass Clustering-Based CNN Approach for Detection of Malignant Melanoma
This paper describes the process of developing a classification model for the effective detection of malignant melanoma, an aggressive type of cancer in skin lesions. Primary focus is given on fine-tuning and improving a state-of-the-art convolutional neural network (CNN) to obtain the optimal ROC-AUC score. The study investigates a variety of artificial intelligence (AI) clustering techniques to train the developed models on a combined dataset of images across data from the 2019 and 2020 IIM-ISIC Melanoma Classification Challenges. The models were evaluated using varying cross-fold validations, with the highest ROC-AUC reaching a score of 99.48%
An AI-Assisted Skincare Routine Recommendation System in XR
In recent years, there has been an increasing interest in the use of artificial intelligence (AI) and extended reality (XR) in the beauty industry. In this paper, we present an AI-assisted skin care recommendation system integrated into an XR platform. The system uses a convolutional neural network (CNN) to analyse an individual's skin type and recommend personalised skin care products in an immersive and interactive manner. Our methodology involves collecting data from individuals through a questionnaire and conducting skin analysis using a provided facial image in an immersive environment. This data is then used to train the CNN model, which recognises the skin type and existing issues and allows the recommendation engine to suggest personalised skin care products. We evaluate our system in terms of the accuracy of the CNN model, which achieves an average score of 93% in correctly classifying existing skin issues. Being integrated into an XR system, this approach has the potential to significantly enhance the beauty industry by providing immersive and engaging experiences to users, leading to more efficient and consistent skincare routines
Effect of the umbrella arch technique modelled as a homogenized area above a cross passage
The stability of tunnel cross passages excavated in soft soil has always been a major challenge. In recent years, new techniques based on the installation of pre-reinforcements before tunnel excavation have been developed to control excavation-induced deformation and surface settlements. In this paper, a finite element numerical simulation was conducted to study the reduction effect of an umbrella vault element modelled as a homogenized area on the deformations induced after the excavation of a cross passage. The results of this study show that the ground deformations can be controlled efficiently by using this type of pre-reinforcement. However, the findings showed that there is no effect of the umbrella arch length on the reduction of the ground deformations. This paper represents a very good demonstration of 3D modelling of tunnel junctions using pre-support techniques; it is the most advanced/appropriate research tool for studying the behaviour of cross passages and is useful as a paradigm for other researchers and practitioners
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