Uniform Refraction in Negative Refractive Index Materials

We study the problem of constructing an optical surface separating two homogeneous, isotropic media, one of which has a negative refractive index. In doing so, we develop a vector form of Snell's law, which is used to study surfaces possessing a certain uniform refraction property, both in the near and far field cases. In the near field problem, unlike the case when both materials have positive refractive index, we show that the resulting surfaces can be neither convex nor concave.Comment: 29 pages, 5 figure

Dynamic Capabilities in Home Health: IT-Enabled Transformation of Post-Acute Care

Home health care can enable shorter hospital stays, reduce re-hospitalization, and contribute to lowered out-of-hospital morbidity and mortality. However, recent changes in Medicare payments and regulations in the US have challenged home health care providers’ business models. Against this backdrop, we draw on the dynamic capability perspective to examine how one home health care provider responded to this challenge over the period 2000-2009 by combining adaptive organization principles and information technology (IT) to transform its post-acute care delivery. The transformation leveraged the organization’s existing dynamic capabilities; improved nursing practices; engaged physicians, nurses, managers, and patients; and implemented remote patient monitoring and other IT-enabled innovations. Integrating information systems and health services literatures, we identify the processes targeted by the transformation, analyze how the provider built adaptive care delivery capability enabled by IT, and demonstrate how the transformation led to improved clinical and financial outcomes. In addition, we offer new insights into the micro-foundations of dynamic capabilities by distinguishing between capabilities at the transactional and transformational levels, and explaining how different types of IT-enabled capabilities shaped, and were shaped by, the home health care provider’s responses to environmental changes

Continuing Medical Education via Telemedicine and Sustainable Improvements to Health

Background. This research aims to investigate the quantitative relationship between telemedicine and online continuing medical education (CME) and to find the optimal CME lectures to be delivered via telemedicine to improve the population's health status. Objective. This study examines the following: (1) What factors foster learning processes in CME via telemedicine? (2) What is the possible role of online CME in health improvement? And (3) How optimal learning processes can be integrated with various health services? Methods. By applying telemedicine experiences in Taiwan over the period 1995-2004, this study uses panel data and the method of ordinary least squares to embed an adequate set of phenomena affecting the provision of online CME lectures versus health status. Results. Analytical results find that a nonlinear online CME-health nexus exists. Increases in the provision of online CME lectures are associated with health improvements. However, after the optimum has been reached, greater provision of online CME lectures may be associated with decreasing population health. Conclusion. Health attainment could be partially viewed as being determined by the achievement of the appropriately providing online CME lectures. This study has evaluated the population's health outcomes and responded to the currently inadequate provision of online CME lectures via telemedicine

Guidelines for the rearrangement of Auschwitz Museum based on web pictures analysis

This paper attempts to answer the question whether the exhibition of the Auschwitz Museum communicates its message properly to the audience or it should be modernised/ rearranged. The aim of the study is so to investigate the way visitors currently look at Auschwitz via the filter of social media. Between November 2014 until January 2015 the number of Instagram pictures with hashtag “Auschwitz” posted on-line nearly doubled to astonishing 80.000 images. In August 2016 the number of images reached over 151.000 making Instagram the essential tool for web picture analysis. In this case, the use of found photography was especially important for the authenticity of correlation between the visitor and one’s architectural surrounding. Specifically, using Instagram and Instagram feed sites, e.g. websta.me we address the questions of how people react to the architecture of the dead camp, how they photograph this place and what is the emphasis of captured images in this particular place

Delivering Diagnostic Quality Video over Mobile Wireless Networks for Telemedicine

In real-time remote diagnosis of emergency medical events, mobility can be enabled by wireless video communications. However, clinical use of this potential advance will depend on definitive and compelling demonstrations of the reliability of diagnostic quality video. Because the medical domain has its own fidelity criteria, it is important to incorporate diagnostic video quality criteria into any video compression system design. To this end, we used flexible algorithms for region-of-interest (ROI) video compression and obtained feedback from medical experts to develop criteria for diagnostically lossless (DL) quality. The design of the system occurred in three steps-measurement of bit rate at which DL quality is achieved through evaluation of videos by medical experts, incorporation of that information into a flexible video encoder through the notion of encoder states, and an encoder state update option based on a built-in quality criterion. Medical experts then evaluated our system for the diagnostic quality of the video, allowing us to verify that it is possible to realize DL quality in the ROI at practical communication data transfer rates, enabling mobile medical assessment over bit-rate limited wireless channels. This work lays the scientific foundation for additional validation through prototyped technology, field testing, and clinical trials

Electronic Health

This article has no abstract

Evidence for As lattice location and Ge bound exciton luminescence in ZnO implanted with 73As and 73Ge

The results of photoluminescence (PL) measurements performed on high quality single crystal ZnO implanted with radioactive 73Ga and 73As, both of which decay to stable 73Ge, are presented. Identical effects are observed in the two cases, with a sharp line at 3.3225(5) eV found to grow in intensity in accordance with the growth rate of the Ge daughter atom populations. On the strength of the well-established result that Ga occupies Zn sites, we conclude from the identical outcomes for 73Ga and 73As implantations that implanted As also preferentially occupies Zn sites. This result supports the findings of others that As preferentially occupies the Zn rather than the O site in ZnO. The thermal quenching energy of the 3.3225(5) eV line is found to be only 2.9(1) meV in contrast to its large spectral shift of 53.4(1) meV with respect to the lowest energy free exciton. The PL is attributed to exciton recombination at neutral Ge double donors on Zn sites involving transitions that leave the donor in an excited state

Preliminary investigations of elemental content, microporosity, and specific surface area of porous rocks using PIXE and X-ray microtomography techniques

Determination of physical properties of porous geological materials is of great importance for oil industry. The knowledge of rocks properties is usually obtained from porosity studies such as pore size distribution, specific surface area determination, and hydrodynamic permeability calculations. This study describes determination of elemental composition and measurements of the particular physical properties of geological samples (porous sandstone rocks) by means of the nuclear and X-ray microprobes at the Institute of Nuclear Physics, Polish Academy of Sciences in Kraków, Poland. The special emphasis has been put on the computed microtomography method. Measurements have been carried out in close cooperation with Department of Geophysics, FGGEP AGH in Kraków, Poland. Chemical composition of the Rotliegend sandstone rock samples (few millimeters diameter), extracted from a borehole at 2679.6 m, 2741.4 m and 2742.4 m depth have been investigated using the 2.2 MeV proton beam (proton induced X-ray emission technique). Next, measurements of the porosity and the specific surface area of the pore space have been carried out using the X-ray microtomography technique. Basing on microtomographic data obtained with the high spatial resolution, simulations of the fluid dynamic in the void space of porous media have been carried out. Lattice Boltzmann method in the 3DQ19 geometrical model has been used in order to predict the hydraulic permeability of the media. In order to avoid viscosity-permeability dependence the multiple-relaxation-time model with half-way bounce back boundary conditions has been used. Computing power-consuming processing has been performed with the use of modern grid infrastructure