364 research outputs found
Land planning through GIS, RS and multicriteria decision analysis. A case study in Sardinia
During the last few years researchers and environmental planners have carried
on their preliminary studies following an interdisciplinary approach. One of the
main issues in this approach is the sustainability of economic development. As a
matter of fact, the importance of the studies related to the distribution and the
limits of natural resources is widely recognized. This can be accomplished more
easily than in present by the use of extremely powerful computer application.
The purpose of this contribution is to demonstrate the usefulness of an integrated
approach of the GIS and of the RS to planning in complex problems of decision
making. Many GIS applications are suited to the input of remote sensing and the
integration of these techniques is now accepted in landscape planning. By means
of GIS and RS, environmental information can be integrated with administrative,
political, social and economic data. GIS, RS and fuzzy logic techniques are used
to assist environmental compatibility studies and decision makin
Recent advances and applications in accessibility modelling
Accessibility is a concept that has become central to physical planning and spatial modelling for more than fifty years. As measure of the relative nearness or proximity of one place and persons to all other places or persons, conceptually linked to Newton\u2019s law of gravity, its origins can be traced back to the 1920s when it was used in location theory and regional economic planning and retail planning.
Accessibility models have in the past decades been applied in several academic fields such as spatial economics, urban geography, rural geography, health geography, time geography, and transport engineering. Many different applications have been developed in these fields and can be categorized in several ways
Here we distinguish four basic perspectives on accessibility: (i) infrastructure-based measures, analyzing the performance or service level of transport infrastructure, (ii) location-based measures, analyzing accessibility of spatially distributed activities, typically on an aggregate level, (iii) person-based measures, founded in the space\u2013time geography, analyzing accessibility at the level of the individual level, and (iv) utility-based
measures, analyzing the welfare benefits that people derive from levels of access to the spatially distributed activities.
It seems with advances in geospatial technology, internet technology, and abundance of detailed spatial data and real-time transport data sets, the field of accessibility modelling is thriving. In this era of data abundance, reflections on the role of accessibility modeling are more than ever important in the search for sound and interdisciplinary accessibility theories and tools. This is the rationale which characterizes the articles included in this Special Issue
To weight or not to weight, that is the question: the design of a composite indicator of landscape fragmentation
Composite indicators (CIs), i.e., combinations of many indicators in a unique synthetizing measure, are useful for disentangling multisector phenomena. Prominent questions concern indicators’ weighting, which implies time-consuming activities and should be properly justified. Landscape fragmentation (LF), the subdivision of habitats in smaller and more isolated patches, has been studied through the composite index of landscape fragmentation (CILF). It was originally proposed by us as an unweighted combination of three LF indicators for the study of the phenomenon in Sardinia, Italy. In this paper, we aim at presenting a weighted release of the CILF and at developing the Hamletian question of whether weighting is worthwhile or not. We focus on the sensitivity of the composite to different algorithms combining three weighting patterns (equalization, extraction by principal component analysis, and expert judgment) and three indicators aggregation rules (weighted average mean, weighted geometric mean, and weighted generalized geometric mean). The exercise provides the reader with meaningful results. Higher sensitivity values signal that the effort of weighting leads to more informative composites. Otherwise, high robustness does not mean that weighting was not worthwhile. Weighting per se can be beneficial for more acceptable and viable decisional processes
INTEGRATING CLIMATE CHANGE ADAPTATION INTO SEA AN ASSESSMENT FOR SARDINIA, ITALY
Climate Change (CC) is recognized as an urgent concern, which implies negative effects on the
environment, such as sea level rise, coastal erosion, fl ooding, droughts, and desertifi cation. It
involves not only the environmental, but also the economic, and social sphere. The impacts
of CC are addressed through two complementary strategies: mitigation and adaptation. The
fi rst one operates on the reasons of CC aiming at preventing or reducing greenhouse gases
emissions, while the second one focuses on the damage they can cause, aiming at minimizing
it or to take advantage of opportunities that may occur.
Strategic Environmental Assessment (SEA) represents a systematic and participatory decisionmaking
support process, aiming at integrating environmental considerations in the elaboration
of plans and programs. While SEA regards explicitly mitigation strategies, so far it still refers
marginally to CC adaptation measures to be carried on when implementing spatial planning
tools at the regional and local scale. The integration of SEA processes with concepts inspired
to adaptation to CCs represents a powerful tool for mainstreaming the corresponding policies
and strategies. In this study, we scrutinize SEA and spatial planning tools issued in Sardinia
(Italy), with reference to their attitude to incorporate possible climate adaptation concerns. We
are interested in proposing and applying a framework based on internationally acknowledged
criteria that need to be met to properly implement climate change adaptation measures and
actions in current spatial planning and SEA practices
Gravity model in the Korean highway
We investigate the traffic flows of the Korean highway system, which contains
both public and private transportation information. We find that the traffic
flow T(ij) between city i and j forms a gravity model, the metaphor of physical
gravity as described in Newton's law of gravity, P(i)P(j)/r(ij)^2, where P(i)
represents the population of city i and r(ij) the distance between cities i and
j. It is also shown that the highway network has a heavy tail even though the
road network is a rather uniform and homogeneous one. Compared to the highway
network, air and public ground transportation establish inhomogeneous systems
and have power-law behaviors.Comment: 13 page
Antidepressant and pro-motivational effects of repeated lamotrigine treatment in a rat model of depressive symptoms
Background: The antiepileptic lamotrigine is approved for maintenance treatment of bipolar disorder and augmentation therapy in treatment-resistant depression. Previous preclinical investigations showed lamotrigine antidepressant-like effects without addressing its possible activity on motivational aspects of anhedonia, a symptom clinically associated with poor treatment response and with blunted mesolimbic dopaminergic responsiveness to salient stimuli in preclinical models. Thus, in rats expressing a depressive-like phenotype we studied whether repeated lamotrigine administration restored behavioral responses to aversive and positive stimuli and the dopaminergic response to sucrose in the nucleus accumbens shell (NAcS), all disrupted by stress exposure. Methods: Depressive-like phenotype was induced in non-food-deprived adult male Sprague-Dawley rats by exposure to a chronic protocol of alternating unavoidable tail-shocks or restraint periods. We examined whether lamotrigine administration (7.5 mg/kg twice a day, i.p.) for 14–21 days restored a) the competence to escape aversive stimuli; b) the motivation to operate in sucrose self-administration protocols; c) the dopaminergic response to sucrose consumption, evaluated measuring phosphorylation levels of cAMP-regulated phosphoprotein Mr 32,000 (DARPP-32) in the NAcS, by immunoblotting. Results: Lamotrigine administration restored the response to aversive stimuli and the motivation to operate for sucrose. Moreover, it reinstated NAcS DARPP-32 phosphorylation changes in response to sucrose consumption. Limitations: The pro-motivational effects of lamotrigine that we report may not completely transpose to clinical use, since anhedonia is a multidimensional construct and the motivational aspects, although relevant, are not the only components. Conclusions: This study shows antidepressant-like and pro-motivational effects of repeated lamotrigine administration in a rat model of depressive symptoms
Spatial correlations in attribute communities
Community detection is an important tool for exploring and classifying the
properties of large complex networks and should be of great help for spatial
networks. Indeed, in addition to their location, nodes in spatial networks can
have attributes such as the language for individuals, or any other
socio-economical feature that we would like to identify in communities. We
discuss in this paper a crucial aspect which was not considered in previous
studies which is the possible existence of correlations between space and
attributes. Introducing a simple toy model in which both space and node
attributes are considered, we discuss the effect of space-attribute
correlations on the results of various community detection methods proposed for
spatial networks in this paper and in previous studies. When space is
irrelevant, our model is equivalent to the stochastic block model which has
been shown to display a detectability-non detectability transition. In the
regime where space dominates the link formation process, most methods can fail
to recover the communities, an effect which is particularly marked when
space-attributes correlations are strong. In this latter case, community
detection methods which remove the spatial component of the network can miss a
large part of the community structure and can lead to incorrect results.Comment: 10 pages and 7 figure
Temporal networks of face-to-face human interactions
The ever increasing adoption of mobile technologies and ubiquitous services
allows to sense human behavior at unprecedented levels of details and scale.
Wearable sensors are opening up a new window on human mobility and proximity at
the finest resolution of face-to-face proximity. As a consequence, empirical
data describing social and behavioral networks are acquiring a longitudinal
dimension that brings forth new challenges for analysis and modeling. Here we
review recent work on the representation and analysis of temporal networks of
face-to-face human proximity, based on large-scale datasets collected in the
context of the SocioPatterns collaboration. We show that the raw behavioral
data can be studied at various levels of coarse-graining, which turn out to be
complementary to one another, with each level exposing different features of
the underlying system. We briefly review a generative model of temporal contact
networks that reproduces some statistical observables. Then, we shift our focus
from surface statistical features to dynamical processes on empirical temporal
networks. We discuss how simple dynamical processes can be used as probes to
expose important features of the interaction patterns, such as burstiness and
causal constraints. We show that simulating dynamical processes on empirical
temporal networks can unveil differences between datasets that would otherwise
look statistically similar. Moreover, we argue that, due to the temporal
heterogeneity of human dynamics, in order to investigate the temporal
properties of spreading processes it may be necessary to abandon the notion of
wall-clock time in favour of an intrinsic notion of time for each individual
node, defined in terms of its activity level. We conclude highlighting several
open research questions raised by the nature of the data at hand.Comment: Chapter of the book "Temporal Networks", Springer, 2013. Series:
Understanding Complex Systems. Holme, Petter; Saram\"aki, Jari (Eds.
The sweet spot in sustainability: a framework for corporate assessment in sugar manufacturing
The assessment of corporate sustainability has become an increasingly important topic, both within academia and in industry. For manufacturing companies to conform to their commitments to sustainable development, a standard and reliable measurement framework is required. There is, however, a lack of sector-specific and empirical research in many areas, including the sugar industry. This paper presents an empirically developed framework for the assessment of corporate sustainability within the Thai sugar industry. Multiple case studies were conducted, and a survey using questionnaires was also employed to enhance the power of generalisation. The developed framework is an accurate and reliable measurement instrument of corporate sustainability, and guidelines to assess qualitative criteria are put forward. The proposed framework can be used for a company’s self-assessment and for guiding practitioners in performance improvement and policy decision-maki
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