3,128 research outputs found

    Imaging multi-age construction settlement behaviour by advanced SAR interferometry

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    This paper focuses on the application of Advanced Satellite Synthetic Aperture Radar Interferometry (A-DInSAR) to subsidence-related issues, with particular reference to ground settlements due to external loads. Beyond the stratigraphic setting and the geotechnical properties of the subsoil, other relevant boundary conditions strongly influence the reliability of remotely sensed data for quantitative analyses and risk mitigation purposes. Because most of the Persistent Scatterer Interferometry (PSI) measurement points (Persistent Scatterers, PSs) lie on structures and infrastructures, the foundation type and the age of a construction are key factors for a proper interpretation of the time series of ground displacements. To exemplify a methodological approach to evaluate these issues, this paper refers to an analysis carried out in the coastal/deltaic plain west of Rome (Rome and Fiumicino municipalities) affected by subsidence and related damages to structures. This region is characterized by a complex geological setting (alternation of recent deposits with low and high compressibilities) and has been subjected to different urbanisation phases starting in the late 1800s, with a strong acceleration in the last few decades. The results of A-DInSAR analyses conducted from 1992 to 2015 have been interpreted in light of high-resolution geological/geotechnical models, the age of the construction, and the types of foundations of the buildings on which the PSs are located. Collection, interpretation, and processing of geo-thematic data were fundamental to obtain high-resolution models; change detection analyses of the land cover allowed us to classify structures/infrastructures in terms of the construction period. Additional information was collected to define the types of foundations, i.e., shallow versus deep foundations. As a result, we found that only by filtering and partitioning the A-DInSAR datasets on the basis of the above-mentioned boundary conditions can the related time series be considered a proxy of the consolidation process governing the subsidence related to external loads as confirmed by a comparison with results from a physically based back analysis based on Terzaghi's theory. Therefore, if properly managed, the A-DInSAR data represents a powerful tool for capturing the evolutionary stage of the process for a single building and has potential for forecasting the behaviour of the terrain-foundation-structure combination

    Exploring the relative importance of crossing number and crossing angle

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    Recent research has indicated that human graph reading performance can be affected by the size of crossing angle. Crossing angle is closely related to another aesthetic criterion: number of edge crossings. Although crossing number has been previously identified as the most important aesthetic, its relative impact on performance of human graph reading is unknown, compared to crossing angle. In this paper, we present an exploratory user study investigating the relative importance between crossing number and crossing angle. This study also aims to further examine the effects of crossing number and crossing angle not only on task performance measured as response time and accuracy, but also on cognitive load and visualization efficiency. The experimental results reinforce the previous findings of the effects of the two aesthetics on graph comprehension. The study demonstrates that on average these two closely related aesthetics together explain 33% of variance in the four usability measures: time, accuracy, mental effort and visualization efficiency, with about 38% of the explained variance being attributed to the crossing angle. Copyright © 2010 ACM

    Non-Abelian vortices in the emergent U(2) gauge theory of the Hubbard model

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    By the spin-fermion formula, the Hubbard model on the honeycomb lattice is represented by a U(2) gauge theory in the mean field method, non-Abelian vortex solutions are constructed based on this theory. The quantization condition shows that the magnetic flux quanta are half-integer. There are 2k2k bosonic zero modes for kk winding vortices. For the fermions, there are 2 zero energy states (ZESs) corresponding to the single elementary vortex. In the vortex core and on the edge, the system are in the semi-metal phase with a spin gap and in the insulator phase with N\'eel order phase, and can be mapped to the superconductor in class A and CI, respectively.Comment: 4pages, 2table

    Essentializing the binary self: individualism and collectivism in cultural neuroscience

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    Within the emerging field of cultural neuroscience (CN) one branch of research focuses on the neural underpinnings of “individualistic/Western” vs. “collectivistic/Eastern” self-views. These studies uncritically adopt essentialist assumptions from classic cross-cultural research, mainly following the tradition of Markus and Kitayama (1991), into the domain of functional neuroimaging. In this perspective article we analyze recent publications and conference proceedings of the 18th Annual Meeting of the Organization for Human Brain Mapping (2012) and problematize the essentialist and simplistic understanding of “culture” in these studies. Further, we argue against the binary structure of the drawn “cultural” comparisons and their underlying Eurocentrism. Finally we scrutinize whether valuations within the constructed binarities bear the risk of constructing and reproducing a postcolonial, orientalist argumentation pattern

    Link between K-absorption edges and thermodynamic properties of warm-dense plasmas established by improved first-principles method

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    A precise calculation that translates shifts of X-ray K-absorption edges to variations of thermodynamic properties allows quantitative characterization of interior thermodynamic properties of warm dense plasmas by X-ray absorption techniques, which provides essential information for inertial confinement fusion and other astrophysical applications. We show that this interpretation can be achieved through an improved first-principles method. Our calculation shows that the shift of K-edges exhibits selective sensitivity to thermal parameters and thus would be a suitable temperature index to warm dense plasmas. We also show with a simple model that the shift of K-edges can be used to detect inhomogeneity inside warm dense plasmas when combined with other experimental tools

    Influence of apical oxygen on the extent of in-plane exchange interaction in cuprate superconductors

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    In high Tc superconductors the magnetic and electronic properties are determined by the probability that valence electrons virtually jump from site to site in the CuO2 planes, a mechanism opposed by on-site Coulomb repulsion and favored by hopping integrals. The spatial extent of the latter is related to transport properties, including superconductivity, and to the dispersion relation of spin excitations (magnons). Here, for three antiferromagnetic parent compounds (single-layer Bi2Sr0.99La1.1CuO6+delta, double-layer Nd1.2Ba1.8Cu3O6 and infinite-layer CaCuO2) differing by the number of apical atoms, we compare the magnetic spectra measured by resonant inelastic x-ray scattering over a significant portion of the reciprocal space and with unprecedented accuracy. We observe that the absence of apical oxygens increases the in-plane hopping range and, in CaCuO2, it leads to a genuine 3D exchange-bond network. These results establish a corresponding relation between the exchange interactions and the crystal structure, and provide fresh insight into the materials dependence of the superconducting transition temperature.Comment: 9 pages, 4 figures, 1 Table, 42 reference

    Development of Foreign Competitor Identification Index (FCII) in Malaysia

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    Most previous studies have dealt with foreign competitors in host country by considering how the contractors compete in international environment. The purpose of this study is to develop a foreign competitor identification index (FCII) by assessing the global orientation of international contractors in Malaysia using various characteristics. The exploratory study is based on the secondary data from Engineering News Record (ENR, 2013) and Construction Industry Development Board (CIDB, 2013) Malaysia. The sampling frame was from the ENR top 250 international contractors operating in more than 100 countries worldwide. Their involvement in international projects includes general building, manufacturing, power, water supply, sewerage/solid waste, industrial process, petroleum, transportation, hazardous waste and telecommunications. Six (6) measurements were used to develop the FCII mode which were based on number of years of experience and number of consecutive years operating in Malaysia, number of countries they are working outside Malaysia, number of projects and number of diversity of projects undertaken in Malaysia, and ranking in ENR. The data was analysed descriptively to make the comparison and establish the findings. Thirty eight (38) out of 250 top international contractors listed by the ENR have been operating in Malaysia. It was observed that that the most competitive contractor with the highest FCII score has more than 12 year of consecutive years working in Malaysia working on 99 projects, operating in more than 20 countries outside Malaysia and ranked at 17th place by the ENR (2013). The study used a sampling frame of population based on ENR. Therefore, the proposed measurements shall be further validated by the subject matter experts. The study will assist local contractors to recognize the foreign competitors in Malaysia and a competitive index model will be further developed to guide the local contractors to prepare themselves to compete with the foreign contractors in Malaysia. Neglecting to properly assess the foreign contractors’ characteristics can lead to poor performance in their local business ventures. This study intends to contribute to an improved understanding foreign contractor’s competitiveness in relation to the local contractors towards the development of the FCII model. Although there have been various models related to competitive index, there is currently no model that attempts to show the effects of foreign contractors on the local contractors

    Prostate cancer in Asia: a collaborative report

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