2,734 research outputs found
Terrain classification by cluster analisys
The digital terrain modelling can be obtained by different methods belonging to two principal categories: deterministic methods (e.g. polinomial and spline functions interpolation, Fourier spectra) and stochastic methods (e.g. least squares collocation and fractals, i.e. the concept of selfsimilarity in probability).
To reach good resul ts, both the fi rst and the second methods need same initial suitable information which can be gained by a preprocessing of data named terrain classification.
In fact, the deterministic methods require to know how is the roughness of the terrain, related to the density of the data (elevations, deformations, etc.) used for the i nterpo 1 at ion, and the stochast i c methods ask for the knowledge of the autocorrelation function of the data.
Moreover, may be useful or very necessary to sp 1 it up the area under consideration in subareas homogeneous according to some parameters, because of different kinds of reasons (too much large initial set of data, so that they can't be processed togheter; very important discontinuities or singularities; etc.).
Last but not least, may be remarkable to test the type of distribution (normal or non-normal) of the subsets obtained by the preceding selection, because the statistical properties of the normal distribution are very important (e.g., least squares linear estimations are the same of maximum likelihood and minimum variance ones)
Expressions of social support: a qualitative analysis of psychotherapy with clients who have experienced trauma
One commonly accepted protective factor, social support, is hypothesized to be both helpful and harmful following exposure to traumatic events (Bonanno, 2008; Ellis, Nixon, & Williamson, 2009; Lyons, 1991). Although at least 10 theoretical models have been proposed to explain the relationship between social support and post-traumatic responses, existing theories do not adequately capture the multidimensional experience of social support, which is comprised of several constructs and structures (e.g., received and perceived support; support functions and content). Moreover, existing social support theories have not been studied in research related to therapy with traumatized clients. The present study, therefore, examined how clients who experienced trauma expressed social support in psychotherapy. A qualitative content analysis was conducted using a directed coding system developed for this study that was based on the constructs and structures commonly discussed in psychology literature on post-traumatic experiences, namely: (a) received support, (b) perceived support, (c) extended support, (d) social support functions, and (e) social support contents. The current study observed that clients who have experienced trauma are likely to mention social support in sessions but that salient factors related to the benefits and harms associated with social support were discussed less. Although many expressions of social support fell into not otherwise specified categories because the quality or type of support experienced was not clearly stated, inductive analysis identified the following salient factors: support needs, relationship elements, planned future support activities, past perceived support, and past support that did not occur. The study also provided support for some existing models of social support and trauma (i.e., network orientation, stress-buffering, erosion, social-cognitive processing, and COR models). Clinical implications related to social support discussions in individual therapy include the need to examine and potentially change therapists\u27 views of social support. Psychotherapists are encouraged to explore the support relationships identified by clients, as well as the quality and types of support experienced and perceived, in order to understand the role and impact of social support and address the benefits and risks associated with support. Clinicians should also recommend that clients engage in adjunctive mutual aid and affiliative support groups
Polarization entangled state measurement on a chip
The emerging strategy to overcome the limitations of bulk quantum optics
consists of taking advantage of the robustness and compactness achievable by
the integrated waveguide technology. Here we report the realization of a
directional coupler, fabricated by femtosecond laser waveguide writing, acting
as an integrated beam splitter able to support polarization encoded qubits.
This maskless and single step technique allows to realize circular transverse
waveguide profiles able to support the propagation of Gaussian modes with any
polarization state. Using this device, we demonstrate the quantum interference
with polarization entangled states and singlet state projection.Comment: Revtex, 5+2 pages (with supplementary information), 4+1 figure
(Re)thinking the city of proximity for Salutogenic purposes.
As centres of population and human activities, nowadays urban environments are simultaneously the main cause of and solution to a growing number of health-related challenges. In this setting, COVID-19 pandemic has helped reiterate this and serves as a wake-up call and an opportunity to rethink the way we approach cities. Aim of this paper is to research what today seems the most promising urban model for long-term individual and global resilience: the ‘‘city of proximity’’, namely about inclusive walkable and cycling environments where people can access all basic destinations within reason- able times and distances from home. Therefore, urban proximity dimension, methodological approach and urban features and functions become the main subject of a quanti- qualitative matrix of comparison of five international case studies centred on the topic, by which it is possible to set out general criteria for such model, along with a methodology to measure all cities in its respect. As a result, residential density, functional mix, pedestrian surface, cycle routes, public transport stops, green areas, schools, cultural facilities, sport facilities, retail services and urban gardens make up the fix components of a comprehensive set of 11+n urban features, whose occurrence is investigated through GIS-based analysis within designated distance ranges, creating a comprehensive assessment framework that is adjustable to all urban contexts worldwide. In the end, the application of such framework to the city of Milan finally helps to validate its effectiveness in
providing a picture of city-wide accessibility to proximity services, and in highlighting the value of integrated analysis in view of shaping public policies and informed planning choices which put health and sustainability at the centre
Algebraic properties of operator precedence languages
This paper presents new results on the algebraic ordering properties of operator precedence grammars and languages. This work was motivated by, and applied to, the mechanical acquisition or inference of operator precedence grammars. A new normal form of operator precedence grammars called homogeneous is defined. An algorithm is given to construct a grammar, called max-grammar, generating the largest language which is compatible with a given precedence matrix. Then the class of free grammars is introduced as a special subclass of operator precedence grammars. It is shown that operator precedence languages corresponding to a given precedence matrix form a Boolean algebra
General rules for bosonic bunching in multimode interferometers
We perform a comprehensive set of experiments that characterize bosonic
bunching of up to 3 photons in interferometers of up to 16 modes. Our
experiments verify two rules that govern bosonic bunching. The first rule,
obtained recently in [1,2], predicts the average behavior of the bunching
probability and is known as the bosonic birthday paradox. The second rule is
new, and establishes a n!-factor quantum enhancement for the probability that
all n bosons bunch in a single output mode, with respect to the case of
distinguishable bosons. Besides its fundamental importance in phenomena such as
Bose-Einstein condensation, bosonic bunching can be exploited in applications
such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure
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