Search results for "14"

How many longitudinal covariate measurements are needed for risk prediction?

2014

Abstract Objective In epidemiologic follow-up studies, many key covariates, such as smoking, use of medication, blood pressure, and cholesterol, are time varying. Because of practical and financial limitations, time-varying covariates cannot be measured continuously, but only at certain prespecified time points. We study how the number of these longitudinal measurements can be chosen cost-efficiently by evaluating the usefulness of the measurements for risk prediction. Study Design and Setting The usefulness is addressed by measuring the improvement in model discrimination between models using different amounts of longitudinal information. We use simulated follow-up data and the data from t…

Gear classification and fault detection using a diffusion map framework

2015

This article proposes a system health monitoring approach that detects abnormal behavior of machines. Diffusion map is used to reduce the dimensionality of training data, which facilitates the classification of newly arriving measurements. The new measurements are handled with Nyström extension. The method is trained and tested with real gear monitoring data from several windmill parks. A machine health index is proposed, showing that data recordings can be classified as working or failing using dimensionality reduction and warning levels in the low dimensional space. The proposed approach can be used with any system that produces high-dimensional measurement data. peerReviewed

How older and younger people see technology in Northern and Southern Europe : Closing the generation gap

2016

Background Mental representations of technology can be affected by many social and biological factors. The aim of this study was to test the effects of two of these factors, age and culture, on how people mentally represent and experience technologies by comparing the conceptions of old and young people in Spain and Finland. Both Spain and Finland are European countries, but they are historically, geographically, and culturally very different. Method The study is framed within the life-based design (LBD) paradigm, where culture and age interact to define particular forms of life in which technology might be used and perceived differently. We hypothesised that there are differences in the me…

Interface Detection Using a Quenched-Noise Version of the Edwards-Wilkinson Equation

2015

We report here a multipurpose dynamic-interface-based segmentation tool, suitable for segmenting planar, cylindrical, and spherical surfaces in 3D. The method is fast enough to be used conveniently even for large images. Its implementation is straightforward and can be easily realized in many environments. Its memory consumption is low, and the set of parameters is small and easy to understand. The method is based on the Edwards-Wilkinson equation, which is traditionally used to model the equilibrium fluctuations of a propagating interface under the influence of temporally and spatially varying noise. We report here an adaptation of this equation into multidimensional image segmentation, an…

Potku – New analysis software for heavy ion elastic recoil detection analysis

2014

Time-of-flight elastic recoil detection (ToF-ERD) analysis software has been developed. The software combines a Python-language graphical front-end with a C code computing back-end in a user-friendly way. The software uses a list of coincident time-of- flight–energy (ToF–E) events as an input. The ToF calibration can be determined with a simple graphical procedure. The graphical interface allows the user to select different elements and isotopes from a ToF–E histogram and to convert the selections to individual elemental energy and depth profiles. The resulting sample composition can be presented as relative or absolute concentrations by integrating the depth profiles over user-defined rang…

Fall Detection Using Location Sensors and Accelerometers

2015

The rapid aging of the world's population is driving the development of pervasive solutions for elder care. These solutions, which often involve fall detection with accelerometers, are accurate in laboratory conditions but can fail in some real-life situations. To overcome this, the authors present the Confidence system, which detects falls mainly with location sensors. A user wears one to four tags. By detecting tag locations with sensors, the system can recognize the user's activity, such as falling and then lying down afterward, as well as the context in terms of the location in the home. The authors used a scenario consisting of events difficult to recognize as falls or nonfalls to comp…

Lattice Boltzmann Simulations at Petascale on Multi-GPU Systems with Asynchronous Data Transfer and Strictly Enforced Memory Read Alignment

2015

The lattice Boltzmann method is a well-established numerical approach for complex fluid flow simulations. Recently general-purpose graphics processing units have become accessible as high-performance computing resources at large-scale. We report on implementing a lattice Boltzmann solver for multi-GPU systems that achieves 0.69 PFLOPS performance on 16384 GPUs. In addition to optimizing the data layout on the GPUs and eliminating the halo sites, we make use of the possibility to overlap data transfer between the host CPU and the device GPU with computing on the GPU. We simulate flow in porous media and measure both strong and weak scaling performance with the emphasis being on a large scale…

Combined in-beam gamma-ray and conversion electron spectroscopy with radioactive ion beams

2013

Plasma instability in the afterglow of ECR discharge sustained in a mirror trap

2014

High-precision measurement of the mass difference between 102Pd and 102Ru

2019

Abstract The Q-value for the neutrinoless double electron capture on 102Pd, Qϵϵ(102Pd), is determined as the atomic mass difference between 102Pd and 102Ru. A precise measurement of the Qϵϵ(102Pd) at the SHIPTRAP Penning trap showed a more than 10σ deviation to the adopted Atomic Mass Evaluation (AME) value. The reliability of the SHIPTRAP measurement was challenged because the AME value was based on numerous experiments including β and electron capture decays and very precise (n, γ) data, all agreeing with each other. To solve the discrepancy, the Qϵϵ(102Pd) has now been determined with the JYFLTRAP Penning trap at the IGISOL facility in the Accelerator Laboratory of the University of Jyva…