1,720,956 research outputs found
Geoprivacy protection of agricultural data
Get PDFA major challenge of sharing spatially explicit agricultural and agri-environmental data is to identify the trade-off between field parcel confidentiality and spatial pattern preservation. in this study, the main drawback of point-based obfuscation was identified and the polygon-based obfuscation methods were designed and developed to overcome these issues
Geospatial data obfuscation methods applied to agricultural data
No full textGeoprivacy protection is a controversial subject within the field of agri-environmental research. Agricultural transformation and digital farming are widely used in the agriculture industry. This enhances sustainable agriculture and subsequently sustainable development and food security. At the same time, such technological advances can mitigate climate change by increasing agricultural productivity while protecting natural resources and reducing the environmental impact of agricultural activities. Digital farming generates a high volume of data including spatial data. This data can be used in data-driven modelling to improve agriculture systems and design and develop more sustainable agricultural policies and services to enhance sustainable agriculture. Sharing and making data accessible to a wide range of researchers and stakeholders is essential to gain maximum use of data. Data privacy and particularly geoprivacy protection is an essential factor when sharing agricultural data and needs urgent investigation.
To date, point-based obfuscation methods are the predominant approaches used to protect object confidentiality with spatial pattern and statistical accuracy preservation. In this research, functionality of point-based obfuscation methods for polygon nature objects was investigated. The terms “non-unique obfuscation” was introduced to the scientific literature for the first time. A high percentage of false-identification and non-unique obfuscation was recognized as the main drawback of point-based obfuscation when applied on polygon centroids as point spatial data.
Agricultural spatial data is often best represented as static polygon data with an association of attributes/properties of a field parcel or farm that includes coordinates, shape, size, topology, the relationship with the surrounding environment, and the impact of external factors on region characteristics that can be used to breach privacy. Agricultural spatial data with unique characteristics that distinguish them from other spatial data, therefore, require different geoprivacy protection techniques. Therefore, for the first time, to achieve a high level of geoprivacy protection, several polygon-based obfuscation methods including PN*Rand, PDonut-k, PDensity-k, PAHilb, PDonut_AHilb and PESOM methods were developed with consideration of these properties and avoidance of the occurrence of false-identification and non-unique obfuscation. The comparison of the performance of obfuscation methods, both point-based and polygon-based, in different aspects using various evaluation metrics indicated that the density-based obfuscation methods provided a better trade-off between level of confidentiality and accuracy. The results demonstrated that PESOM method maintained a high level of geoprivacy protection and absolute environmental and climatic clustering preservation with no false identification and non-unique obfuscation risk.
Following on from this. a case study was conducted to showcase the useability of obfuscated data to solve real world problems and highlight the importance of the choice of obfuscation method in outcome and suitability of obfuscated data for a certain purpose. Several evaluation metrics were developed to examine and assess the performance of obfuscation methods in terms of determining the level of privacy protection and spatial pattern preservation, and statistical accuracy. The results confirm the importance of choosing the right obfuscation method based on the influence of internal and external features on the results of the data-driven model. Therefore, the results of this research should be of wide interest to those working in GIScience, agri-environmental research, and computer science, and be of relevance to researchers and data managers
Data conditioning and climate sensitivity analysis of a probablistic rainfall-runoff model
Get PDFThe Munster Blackwater catchment, in the South West of Ireland, was regularly subject to flooding, prior to flood allevation works. The towns of Mallow and Fermoy within the catchment suffered many disturbances for their inhabitants with sometimes severe economic losses. A good knowledge of rainfall-runoff processes is important in order to understand the causes of flooding to be able to develop new infrastructure to manage flooding. The first part of this project focuses on the rainfall and river flow data collection from different sources: the 15-minute time step precipitation data from the OPW, the 15-minute river level/river flow from the OPW and the EPA and the precipitation data from MÉRA (Met Éireann ReAnalysis- Climate ReAnalysis). MÉRA is a very high resolution climate reanalysis dataset which was used to calculate the monthly and annual rainfall in a specific year, for example for 2010 for selected locations (the nearest point to each rain gauge). Initial analysis of the measured OPW data shows significant numbers of missing values and outliers for the precipitation data. A method was developed to cluster the rain gauges with similar precipitation patterns based on the amount of precipitation of the nearest points to these rain gauges from MÉRA. Then a gap filling method was applied in each cluster to fill the missing values of each rain gauge with its cluster members. Other methods were also examined to obtain quality controlled data. The second part of this project applies a conceptual hydrological model, PDM (Probability Distributed Model) developed by Moore (Moore, 2007) to the Munster Blackwater catchment. The model considers each point of a catchment as a single storage unit with a specific storage capacity (depth) that can be described by a Pareto distribution. PDM is suitable for a variety of catchments, and has minimal data and computational requirements. The input is 15-minute precipitation data from different rain gauges and 15-minute river level/river flow data from river stations along the river. The calibration was applied on three subcatchments of the Munster Blackwater catchment. The validation was applied for years between 2010 to 2017. The calibrations and validations indicate that the PDM model can explain most of the variability of observed flows in the different subcatchments over a period of years, especially when a high standard of data quality is available, for example in 2015. Then validation of the model for flood events was examined. Validation was applied for the highest flood event in each year during 2010 to 2017. The accuracy of the model runs are different for each subcatchment with the best accuracy of 93% in the Dromcummer subcatchment and the accuracies in Mallow Rail BR and Killavullen being 80 % and 78% respectively. The model estimates the peak and low flow very well in Dromcummer. The computed flow is underestimated in Mallow and overestimated in Killavullen. The third part of the project is to use the PDM model in a precipitation and river flow sensitivity analysis. This was achieved by increasing the precipitation amounts in the datasets by 10, 15, 20, 25 and 30% to examine how the peak flows and low flows respond. It was found that the peak flows increase by amounts similar to the precipitation increases. The low flows increase at a much lower rate than the precipitation increases. It is known that in a scenario of climate change for a warming world that the precipitation increases by a maximum of 7% per degree C increase in accordance with the Clausius-Clapeyron equation. However as a warming world also increases evaporation and will likely impact the soil moisture status, it is considered that flood flows might increase at a rate less than the precipitation increases. This can be examined by increasing the value of potential evaporation by 10, 15, 20, 25 and 30% .These conditions were not included in this and it is ecommended that further research be done in this area for Ireland
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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