1,720,962 research outputs found
Insights into the Effect of Urban Morphology and Land Cover on Land Surface and Air Temperatures in the Metropolitan City of Milan (Italy) Using Satellite Imagery and In Situ Measurements
Full text linkWith a concentration of people, activities, and infrastructures, urban areas are particularly vulnerable to the negative effects of climate change. Among others, the intensification of the Urban Heat Island (UHI) effect is leading to an increased impact on citizen health and the urban ecosystem. In this context, this study aims to investigate the effect of urban morphology and land cover composition-which are established by exploiting the Local Climate Zone (LCZ) classification system-on two urban climate indicators, i.e., Land Surface Temperature (LST) and air temperature. The study area is the Metropolitan City of Milan (northern Italy). LCZ and LST maps are derived by leveraging satellite imagery and building height datasets. Both authoritative and crowdsourced in situ measurements are used for the analysis of air temperature. Several experiments are run to investigate the mutual relation between LCZ, LST, and air temperature by measuring LST and air temperature patterns in different LCZs and periods. Besides a strong temporal correlation between LST and air temperature, results point out vegetation and natural areas as major mitigating factors of both variables. On the other hand, higher buildings turn out to increase local air temperature while buffering LST values. A way lower influence of building density is measured, with compact building areas experiencing slightly higher air temperature yet no significant differences in terms of LST. These outcomes provide valuable tools to urban planners and stakeholders for implementing evidence-based UHI mitigation strategies
Openness and Community Geospatial Science for Monitoring SDGs - An Example From Tanzania
Full text linkThis chapter focuses on two aspects that enable the monitoring of the United Nations (UN) sustainable development goals (SDGs): openness and community geospatial science
An Evaluation Framework for Assessing the Impact of Location Privacy on Geospatial Analysis
No full textThe need for addressing geoprivacy in location based services has increased the offer of mechanisms that protect location information, however, these algorithms are not always developed to ensure the usability of the data and therefore, their adoption is not wide. In this work, a framework is presented to evaluate the effects of geoprivacy mechanisms on the quality of geodata to provide insights into how the data is affected for geospatial analysis. For this purpose, a toolkit of indices was developed to evaluate different characteristics of the data before and after a geoprivacy mechanism is implemented, providing a criterion to select one of them. The indices measure the changes in the presence of clusters through the quantification of hotspots in hotspot analysis and the difference observed in heatmaps of the concentration of the geodata. Variations in global indices like the Nearest Neighbor Index (NNI) and the orientation of the standard deviational ellipse are also measured. For demonstration, the data of crime arrests in New York was used for the month of January in 2017 and 2018. Five mechanisms were tested with different settings, resulting with the NRand-K algorithm producing fewer alterations to the reference data, preserving its initial characteristics better than the other mechanisms
Citizen Science Impact on Environmental Monitoring towards SDGs Indicators: The CASE of SIMILE Project
Full text linkThis study presents the ongoing activities of citizen science (CS) monitoring of lake water quality that was developed in the SIMILE project. After presenting the tools and the initiatives that were implemented to gather volunteer contributions, the CS data are analyzed: to understand the main factors driving the contribution provided by citizens, through a proximity analysis using hierarchical clustering; to evaluate their added value and complementary nature in view of the proposed integrated lake monitoring with respect to remote sensing (RS) water quality parameters maps and in situ high-frequency monitoring (HFM) data that were acquired in the framework of SIMILE project, through an intercomparison of temperature data; and to highlight water quality patterns in the lakes under study. It is then discussed how the project outcomes could directly or indirectly contribute to the measurement of specific Sustainable Development Goals (SDGs) indicators highlighting the potential impact of CS activities. The conclusions highlight the complementary nature of CS and the need of supporting activities for a continuous lake water quality monitoring. The possibility for the partner local authorities to maintain the CS monitoring establishing a Citizen Observatory (CO) and the opportunity to extend the SIMILE approach to neighboring lakes and beyond is also discussed
High-resolution land cover classification: cost-effective approach for extraction of reliable training data from existing land cover datasets
Full text linkThere has been a significant increase in the availability of global high-resolution land cover (HRLC) datasets due to growing demand and favorable technological advancements. However, this has brought forth the challenge of collecting reference data with a high level of detail for global extents. While photo-interpretation is considered optimal for collecting quality training data for global HRLC mapping, some producers of existing HRLCs use less trustworthy sources, such as existing land cover at a lower resolution, to reduce costs. This work proposes a methodology to extract the most accurate parts of existing HRLCs in response to the challenge of providing reliable reference data at a low cost. The methodology combines existing HRLCs by intersection, and the output represents a Map Of Land Cover Agreement (MOLCA) that can be utilized for selecting training samples. MOLCA's effectiveness was demonstrated through HRLC map production in Africa, in which it generated 48,000 samples. The best classification test had an overall accuracy of 78%. This level of accuracy is comparable to or better than the accuracy of existing HRLCs obtained from more expensive sources of training data, such as photo-interpretation, highlighting the cost-effectiveness and reliability potential of the developed methodology in supporting global HRLC production
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
