1,444 research outputs found
Image reconstruction from scattered Radon data by weighted positive definite kernel functions
We propose a novel kernel-based method for image reconstruction from scattered Radon data. To this end, we employ generalized HermiteâBirkhoff interpolation by positive definite kernel functions. For radial kernels, however, a straightforward application of the generalized HermiteâBirkhoff interpolation method fails to work, as we prove in this paper. To obtain a well-posed reconstruction scheme for scattered Radon data, we introduce a new class of weighted positive definite kernels, which are symmetric but not radially symmetric. By our construction, the resulting weighted kernels are combinations of radial positive definite kernels and positive weight functions. This yields very flexible image reconstruction methods, which work for arbitrary distributions of Radon lines. We develop suitable representations for the weighted basis functions and the symmetric positive definite kernel matrices that are resulting from the proposed reconstruction scheme. For the relevant special case, where Gaussian radial kernels are combined with Gaussian weights, explicit formulae for the weighted Gaussian basis functions and the kernel matrices are given. Supporting numerical examples are finally presented
RBF approximation of large datasets by partition of unity and local stabilization
We present an algorithm to approximate large dataset by Radial Basis Function
(RBF) techniques. The method couples a fast domain decomposition procedure with a
localized stabilization method. The resulting algorithm can efficiently deal with large
problems and it is robust with respect to the typical instability of kernel methods
Partition of unity interpolation using stable kernel-based techniques
In this paper we propose a new stable and accurate approximation technique
which is extremely effective for interpolating large scattered data sets. The
Partition of Unity (PU) method is performed considering Radial Basis Functions
(RBFs) as local approximants and using locally supported weights. In
particular, the approach consists in computing, for each PU subdomain, a stable
basis. Such technique, taking advantage of the local scheme, leads to a
significant benefit in terms of stability, especially for flat kernels.
Furthermore, an optimized searching procedure is applied to build the local
stable bases, thus rendering the method more efficient
Projeto de arborização da praça da Torre do Castelo.
Em virtude da comemoração dos 240 anos da cidade de Campinas, a Embrapa Monitoramento por SatĂ©lite e o NĂșcleo de Estudos e Pesquisas Ambientais da Universidade Estadual de Campinas (Nepam/Unicamp) apresentam um projeto para rearborizar a Praça da Torre do Castelo, um dos principais cartĂ”es postais da cidade. A partir das informaçÔes histĂłricas da vegetação de Campinas e de pesquisas com moradores e frequentadores do local, criou-se um projeto que insere espĂ©cies nativas regionais, com coerĂȘncia de cores e de estilo e respeito a arquitetura do local e a segurança dos transeuntes.bitstream/item/103780/1/DC-105.pd
5-th Dolomites Workshop on Constructive Approximation and Applications â Special Issue dedicated to Robert Schaback on the occasion of his 75th birthday
The guest editors discuss the highlights of the 5-th Dolomites Workshop on Constructive Approximation and Applications, and briefly introduce the papers included in this special issue
Feasibility limits of using low-grade industrial waste heat in symbiotic district heating and cooling networks
Abstract: Low-grade waste heat is an underutilized resource in process industries, which may consider investing in urban symbiosis projects that provide heating and cooling to proximal urban areas through district energy networks. A long distance between industrial areas and residential users is a barrier to the feasibility of such projects, given the high capital intensity of infrastructure, and alternative uses of waste heat, such as power generation, may be more profitable, in spite of limited efficiency. This paper introduces a parametric approach to explore the economic feasibility limits of waste heat-based district heating and cooling (DHC) of remote residential buildings depending on network extension. A parametric model for the comparative water\u2013energy\u2013carbon nexus analysis of waste heat-based DHC and Organic Rankine Cycles is also introduced, and applied to an Italian and to an Austrian setting. The results show that, for a generic 4\ua0MW industrial waste heat flow steadily available at 95\ua0\ub0C, district heating and cooling is the best option from an energy\u2013carbon perspective in both countries. Power generation is the best option in terms of water footprint in most scenarios, and is economically preferable to DHC in Italy. Maximum DHC feasibility threshold distances are in line with literature, and may reach up to 30\ua0km for waste heat flows of 30\ua0MW in Austria. However, preferability threshold distances, above which waste heat-to-power outperforms DHC from an economic viewpoint, are shorter, in the order of 20\ua0km in Austria and 10\ua0km in Italy for 30\ua0MW waste heat flows. Graphic abstract: [Figure not available: see fulltext.]
Carbon and water footprint of energy saving options for the air conditioning of electric cabins at industrial sites
Low knowledge and awareness of monoclonal gammopathy of undetermined significance (MGUS) among general practitioners
Acknowledgements The authors would like to take this opportunity to thank the organisers of the WONCA Europe 2017 conference and the General Practitioners/Traineeâs for participating in this study. Funding At the time of writing, Dr Charlene McShane was in receipt of a Cancer Research UK Population Science Postdoctoral Research Fellowship (C51094/A18267)Peer reviewedPublisher PD
Effects of eight months of whole body vibration training on hip bone mass in older women
Objective: The aim of this study was to examine the effect of 8 months of whole-body vibration training on bone mass in octogenarian women.
Method: Thirty-seven women (aged 82.4 [SD=5.7] years) voluntarily participated in this study. The vibration group (n=19) trained on a vibration platform twice a week (20 Hz and 2 mm) whereas controls (n=18) did not participate in any training program. Bone mass was measured by dual-energy X-ray absorptiometry at the hip region. General linear repeated measures ANOVA (group by time) was used to examine the effect of whole body vibration on bone mass changes.
Results: After the intervention, in all the hip regions (total hip, femoral neck, trochanter, intertrochanter, Wardâs area), no statistically significant changes in bone mass were found.
Conclusion: Eight months of whole body vibration training (twice a week) in elderly women do not produce osteogenic effects
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