721 research outputs found
Random projection to preserve patient privacy
With the availability of accessible and widely used cloud services, it is natural that large components of healthcare systems migrate to them; for example, patient databases can be stored and processed in the cloud. Such cloud services provide enhanced flexibility and additional gains, such as availability, ease of data share, and so on. This trend poses serious threats regarding the privacy of the patients and the trust that an individual must put into the healthcare system itself. Thus, there is a strong need of privacy preservation, achieved through a variety of different approaches. In this paper, we study the application of a random projection-based approach to patient data as a means to achieve two goals: (1) provably mask the identity of users under some adversarial-attack settings, (2) preserve enough information to allow for aggregate data analysis and application of machine-learning techniques. As far as we know, such approaches have not been applied and tested on medical data. We analyze the tradeoff between the loss of accuracy on the outcome of machine-learning algorithms and the resilience against an adversary. We show that random projections proved to be strong against known input/output attacks while offering high quality data, as long as the projected space is smaller than the original space, and as long as the amount of leaked data available to the adversary is limited
Chemical bond and electronic states in the CaF2-Si(111) and Ca-Si(111) interfaces
The first stage of formation of the CaF2-Si(111) and Ca-Si(111) interfaces is studied through the employment of the surface linear-muffin-tin-orbital approach in the atomic-sphere approximation. The interfaces are simulated by monolayers of F-Ca and Ca on Si(111), respectively. Both valence- and core-electron states have been calculated: their analysis gives important information about the nature of the Ca-Si and Ca-F bonds. These results are successfully compared with the available experimental data. The importance of considering the Madelung contribution in the interpretation of surface-core-level shifts is pointed out
Effectiveness of Sand Drains in Peaty Soil in a Case of Differential Settlement Recovering
The result obtained in a case history of differential settlement recovery are reported. The effectiveness of sand drains in peaty soil is questioned. The importance and the mutual influence of the primary and secondary settlement are discussed. Remarks are made on the value of secondary settlement coefficient
Recovering Differential Settlements by Vertical Drains
The differential settlement recovering of a large six storeys building by means of overloading and vertical drains is described. The results are discussed in relation with the geotechnical characteristics of the soil and by numerical analyses of the settlement curves
Developing the MTO Formalism
We review the simple linear muffin-tin orbital method in the atomic-spheres
approximation and a tight-binding representation (TB-LMTO-ASA method), and show
how it can be generalized to an accurate and robust Nth order muffin-tin
orbital (NMTO) method without increasing the size of the basis set and without
complicating the formalism. On the contrary, downfolding is now more efficient
and the formalism is simpler and closer to that of screened multiple-scattering
theory. The NMTO method allows one to solve the single-electron Schroedinger
equation for a MT-potential -in which the MT-wells may overlap- using basis
sets which are arbitrarily minimal. The substantial increase in accuracy over
the LMTO-ASA method is achieved by substitution of the energy-dependent partial
waves by so-called kinked partial waves, which have tails attached to them, and
by using these kinked partial waves at N+1 arbitrary energies to construct the
set of NMTOs. For N=1 and the two energies chosen infinitesimally close, the
NMTOs are simply the 3rd-generation LMTOs. Increasing N, widens the energy
window, inside which accurate results are obtained, and increases the range of
the orbitals, but it does not increase the size of the basis set and therefore
does not change the number of bands obtained. The price for reducing the size
of the basis set through downfolding, is a reduction in the number of bands
accounted for and -unless N is increased- a narrowing of the energy window
inside which these bands are accurate. A method for obtaining orthonormal NMTO
sets is given and several applications are presented.Comment: 85 pages, Latex2e, Springer style, to be published in: Lecture notes
in Physics, edited by H. Dreysse, (Springer Verlag
Third-Generation TB-LMTO
We describe the screened Korringa-Kohn-Rostoker (KKR) method and the
third-generation linear muffin-tin orbital (LMTO) method for solving the
single-particle Schroedinger equation for a MT potential. The simple and
popular formalism which previously resulted from the atomic-spheres
approximation (ASA) now holds in general, that is, it includes downfolding and
the combined correction. Downfolding to few-orbital, possibly short-ranged,
low-energy, and possibly orthonormal Hamiltonians now works exceedingly well,
as is demonstrated for a high-temperature superconductor. First-principles sp3
and sp3d5 TB Hamiltonians for the valence and lowest conduction bands of
silicon are derived. Finally, we prove that the new method treats overlap of
the potential wells correctly to leading order and we demonstrate how this can
be exploited to get rid of the empty spheres in the diamond structure.Comment: latex2e, 32 printed pages, Postscript figs, to be published in:
Tight-Binding Approach to Computational Materials Science, MRS Symposia
Proceedings No. 491 (MRS, Pittsburgh, 1998
Acceptance of COVID-19 vaccine among persons experiencing homelessness in the City of Rome, Italy
Objective: Vulnerable populations are being more severely impacted by the ongoing pandemic, and the recent release of vaccines for Coronavirus Disease 19 (COVID-19) may offer them protection. The aim of this study was to investigate the willingness of homeless persons to be vaccinated against COVID-19; secondary aims were to analyze the immunization coverage for other conditions. Patients and methods: The acceptance of COVID-19 vaccine and immunization coverage for other conditions were investigated through a form in 112 persons experiencing homelessness referring to the primary care medical services of the Eleemosynaria Apostolica, Holy See. Results: Most subjects, with a male preponderance, were willing to be vaccinated against COVID-19 (64.3%), 3.6% were unsure and 32.1% preferred not to be vaccinated. When answering questions on the immunization coverage for tuberculosis and hepatitis A and B, most subjects reported not to be vaccinated (48.2%, 56.2% and 55.3%, respectively) or did not know (33%, 28.6% and 27.7%). Conclusions: A significant portion of our sample declared to be willing to be vaccinated against COVID-19. It would be auspicious that the recent statements from several countries on the importance to extend COVID-19 vaccination to fragile populations be followed by the distribution of the vaccine to these populations
Patterns of CT lung injury and toxicity after stereotactic radiotherapy delivered with helical tomotherapy in early stage medically inoperable NSCLC
To evaluate toxicity and patterns of radiologic lung injury on CT images after hypofractionated image-guided stereotactic body radiotherapy (SBRT) delivered with helical tomotherapy (HT) in medically early stage inoperable non-small-cell lung cancer (NSCLC)
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