ONE ARABESQUE IN THE SMALL WORLD OF OD WEBMAPS

Abstract. Arabesque is an application for the exploration and geovisualisation of origin-destination flows (or spatial networks), developed within the framework of the Univ. Gustave Eiffel (ex. IFSTTAR)-funded research project geographic flow visualisation (gflowiz) geoflowiz, in collaboration with the CNRS. It allows both the exploration and the filtering of OD data and their representation, with a strong emphasis on geographic information layering and features' semiology. The key-objective is to propose an easy way to produce a modern cartography (a geovisualisation) of thematic flows (e.g. bilateral flow volume), at several geographic scales, even from your own datasets. The objective of this article is to position Arabesque in the range of geoweb applications for producing flow maps, by comparing its functionalities with those of similar web applications – Magrit, Kepler.gl, flowmap.blue – pointing out their respective advantages and limitations. The analysis of its functionalities is compared on the same flow dataset – MOBSCO, i.e. a dataset describing the school mobility of French pupils and students on a given year – for a practical and empirical “validation” of its contributions. We demonstrate that the configurations and appearances of these tools’ visual output depend largely on the culture of their developers, and on the use and audiences for which they have been developed.

Download Full-text

A REFINED ESTIMATE OF LAVA FLOW VOLUME OF THE DECCAN TRAPS (INDIA) USING GEOGRAPHIC INFORMATION SYSTEMS

10.1130/abs/2017ne-290608 ◽

2017 ◽

Author(s):

Nicholas Barber ◽

◽

Anne E. Jay ◽

Loyc Vanderkluysen

Keyword(s):

Information Systems ◽

Geographic Information Systems ◽

Lava Flow ◽

Geographic Information ◽

Deccan Traps ◽

Flow Volume ◽

Refined Estimate

Download Full-text

Untangling origin-destination flows in geographic information systems

Information Visualization ◽

10.1177/1473871617738122 ◽

2017 ◽

Vol 18 (1) ◽

pp. 153-172 ◽

Cited By ~ 12

Author(s):

Anita Graser ◽

Johanna Schmidt ◽

Florian Roth ◽

Norbert Brändle

Keyword(s):

Information System ◽

Information Systems ◽

Geographic Information System ◽

Geographic Information Systems ◽

Spatial Data ◽

Geographic Information ◽

Data Sets ◽

Flow Maps ◽

Local Strength ◽

Edge Bundling

Origin–destination flow maps are a popular option to visualize connections between different spatial locations, where specific routes between the origin and destination are unknown or irrelevant. Visualizing origin–destination flows is challenging mainly due to visual clutter which appears quickly as data sets grow. Clutter reduction techniques are intensively explored in the information visualization and cartography domains. However, current automatic techniques for origin–destination flow visualization, such as edge bundling, are not available in geographic information systems which are widely used to visualize spatial data, such as origin–destination flows. In this article, we explore the applicability of edge bundling to spatial data sets and necessary adaptations under the constraints inherent to platform-independent geographic information system scripting environments. We propose (1) a new clustering technique for origin–destination flows that provides within-cluster consistency to speed up computations, (2) an edge bundling approach based on force-directed edge bundling employing matrix computations, (3) a new technique to determine the local strength of a bundle leveraging spatial indexes, and (4) a geographic information system–based technique to spatially offset bundles describing different flow directions. Finally, we evaluate our method by applying it to origin–destination flow data sets with a wide variety of different data characteristics.

Download Full-text

Quantum GIS plugin for Czech cadastral data

Geoinformatics FCE CTU ◽

10.14311/gi.8.7 ◽

2012 ◽

Vol 8 ◽

pp. 91-98

Author(s):

Anna Kratochvílová ◽

Václav Petráš

Keyword(s):

Information System ◽

Geographic Information System ◽

Web Applications ◽

Geographic Information ◽

Data Format ◽

Specific Data ◽

Cross Platform ◽

Easy Search ◽

Exchange Data ◽

The Way

This paper presents new Quantum GIS plugin for Czech cadastral data and its development. QGIS is a rapidly developing cross-platform desktop Geographic Information System (GIS) released under the GNU GPL. QGIS is written in C++, and uses the Qt library. The plugin is developed in C++, too. The new plugin can work with Czech cadastral data in the new Czech cadastral exchange data format called VFK (or NVF). Data are accessed through VFK driver of the OGR library. The plugin should facilitate the work with cadastral data by easy search and presenting well arranged information. Information is displayed in the way similar to web applications, thus the control is friendly and familiar for users. The plugin supports interaction with map using QGIS functionality and it is able to export various cadastral reports. This paper provides ideas which can be generalized to develop QGIS plugin dealing with specific data.

Download Full-text

Cross-Layer Optimization and Cascadability of Optical Switches in Fiber Optic Data Networks

Journal of Optical Communications ◽

10.1515/joc-2018-0142 ◽

2018 ◽

Vol 0 (0) ◽

Author(s):

Ravi Kumar ◽

Anurag Tripathi

Keyword(s):

Data Center ◽

Web Applications ◽

Fiber Optic ◽

Optical Switch ◽

Small World ◽

Optical Switches ◽

Data Networks ◽

Cross Layer ◽

Cross Layer Optimization ◽

Energy Consumption Analysis

AbstractIn the most recent years, developing web applications such as cloud computing, Big Data and latest cell phone applications have added more workload on the server centers. With the expansion on the network traffic, the consumption of power also increases. In past to reduce power consumption AWG based optical switch designs are proposed, and BER, energy consumption analysis has been carried out in isolated switch. In this paper, cascadability analysis of optical switches in fiber optic and data center networks is presented, and BER is calculated for isolated and cascaded switches. In fixing switch size concepts of graph theory and small world model are used. The packet loss performance is also simulated under different loading and buffering conditions. Finally, cross layer optimization concept is discussed in fixing various switch parameters.

Download Full-text

A Suite of Metrics for Evaluating Client-Side web Applications: An Empirical Validation

2020 XLVI Latin American Computing Conference (CLEI) ◽

10.1109/clei52000.2020.00023 ◽

2020 ◽

Author(s):

Luis Felipe Henao Lopez ◽

Maricela Gomez Martinez ◽

Albeiro Espinosa Bedoya

Keyword(s):

Web Applications ◽

Empirical Validation ◽

Client Side

Download Full-text

ONTOLOGICAL ASSESSMENT AND SIGNIFICANCE OF SEMANTIC LEVELS OF TAGS IN OPENSTREETMAP

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-4-w18-29-2019 ◽

2019 ◽

Vol XLII-4/W18 ◽

pp. 29-33

Author(s):

S. Ahmadian ◽

F. Hakimpour

Keyword(s):

Set Theory ◽

Rough Set ◽

Web Applications ◽

Rough Set Theory ◽

Semantic Knowledge ◽

Geographic Information ◽

Data Sources ◽

Semantic Heterogeneity ◽

The Web

Abstract. User-generated contents are developing rapidly through VGI and contributors create the tags through the Web applications in a free mechanism. Semantic Knowledge in VGI like other user-generated contents needs to be combined with other authoritative data sources. One of the main challenges of integration is the semantic heterogeneity of user-generated contents which are describing the geographical objects as POIs. Geographical objects can be described in different semantic levels such as purpose or function. Significance of semantic levels defines the importance of related attributes. Analysis of significance for semantic levels of different POIs can be considered as a base to enhance the semantic quality of VGI. This paper proposes an approach based on the notions of rough set theory to measure the significance of semantic levels of tags which are applied to describe the buildings in OpenStreetMap. The proposed approach is implemented for tags which are applied to describe buildings in OpenStreetMap. Results show the high significance for tags which describing the semantic levels of geographic information constructs and purpose/ function for buildings.

Download Full-text

Using Eye Tracking to Evaluate the Usability of Flow Maps

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi7070281 ◽

2018 ◽

Vol 7 (7) ◽

pp. 281 ◽

Cited By ~ 7

Author(s):

Weihua Dong ◽

Shengkai Wang ◽

Yizhou Chen ◽

Liqiu Meng

Keyword(s):

Eye Tracking ◽

Empirical Studies ◽

Flow Volume ◽

Flow Maps ◽

Color Gradient ◽

Color Gradients ◽

Produce Flow ◽

Areas Of Interest ◽

Straight Lines

Flow maps allow users to perceive not only the location where interactions take place, but also the direction and volume of events. Previous studies have proposed numerous methods to produce flow maps. However, how to evaluate the usability of flow maps has not been well documented. In this study, we combined eye-tracking and questionnaire methods to evaluate the usability of flow maps through comparisons between (a) straight lines and curves and (b) line thicknesses and color gradients. The results show that curved flows are more effective than straight flows. Maps with curved flows have more correct answers, fixations, and percentages of fixations in areas of interest. Furthermore, we find that the curved flows require longer finish times but exhibit smaller times to first fixation than straight flows. In addition, we find that using color gradients to indicate the flow volume is significantly more effective than the application of different line thicknesses, which is mainly reflected by the presence of more correct answers in the color-gradient group. These empirical studies could help improve the usability of flow maps employed to visualize geo-data.

Download Full-text

COVID-19 Flow-Maps an open geographic information system on COVID-19 and human mobility for Spain

Scientific Data ◽

10.1038/s41597-021-01093-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Miguel Ponce-de-Leon ◽

Javier del Valle ◽

José María Fernandez ◽

Marc Bernardo ◽

Davide Cirillo ◽

...

Keyword(s):

Information System ◽

Geographic Information System ◽

Human Mobility ◽

Social Contact ◽

Geographic Information ◽

Mobile Phone Data ◽

Population Mobility ◽

Data Set ◽

Flow Maps ◽

Pharmaceutical Interventions

AbstractCOVID-19 is an infectious disease caused by the SARS-CoV-2 virus, which has spread all over the world leading to a global pandemic. The fast progression of COVID-19 has been mainly related to the high contagion rate of the virus and the worldwide mobility of humans. In the absence of pharmacological therapies, governments from different countries have introduced several non-pharmaceutical interventions to reduce human mobility and social contact. Several studies based on Anonymized Mobile Phone Data have been published analysing the relationship between human mobility and the spread of coronavirus. However, to our knowledge, none of these data-sets integrates cross-referenced geo-localised data on human mobility and COVID-19 cases into one all-inclusive open resource. Herein we present COVID-19 Flow-Maps, a cross-referenced Geographic Information System that integrates regularly updated time-series accounting for population mobility and daily reports of COVID-19 cases in Spain at different scales of time spatial resolution. This integrated and up-to-date data-set can be used to analyse the human dynamics to guide and support the design of more effective non-pharmaceutical interventions.

Download Full-text