1,721,035 research outputs found
Framy: Visualizing Geographic Data on Mobile Interfaces
No full textWhen using a mobile device for navigating and querying a map, some
visualisation and usability problems may arise due to small screens and limited
interaction modes allowed by such devices. Recently, researchers have devoted
their efforts to overcome these issues by introducing innovative approaches for
developing advanced interfaces, capable of providing users with analytical
information as well as visual summary of data. In this article, we propose a new
visualisation technique, named Framy, which exploits a novel interaction
metaphor for picture frames to provide hints about off-screen objects. It was
conceived to cover a wider range of spatial data visualisation tasks, which may
simultaneously involve different geographic layers. The technique has been
embedded inside a mobile GIS application, MapGIS, designed to perform typical
GIS operations and queries on mobile devices. A usability study has been
performed in order to verify the benefits in efficacy, efficiency and subjective
satisfaction coming from the adoption of Framy within the system
A Visualization Technique for the Emergency Management by Means of Mobile Devices
No full textWorkshop GeoVA(t) – Geospatial Visual Analytics: Focus on Time nell’ambito della 13th AGILE International Conference on Geographic Information Science. 10-11 May 2010 - Guimarães, Portuga
Petroglyph Classification using the Image Distortion Model
No full textPetroglyphs are prehistoric engravings in stone unrevealing stories of ancient life and describing a conception of the world transmitted till today. The great number of sites and the high variability in the artifacts makes their study a very complex task. Thus, the development of tools which automate the recognition of petroglyphs is essential not only for supporting archaeologist to understand petroglyph symbols and relationships, but also for the anthropol- ogists who are interested in the evolution of human beings. However, many challenges exist in the recognition of petroglyph reliefs mainly due to their high level of distortion and variability. To address these challenges, in this paper we present an automatic image-based petroglyph recognizer that focuses on the visual appearance of the petroglyph in order to assess the similarity of petroglyph reliefs. The proposed matching algorithm is based on an image deformation model that is computationally efficient and robust to local distortions. The classification system has been applied to an image database containing 17 classes of petroglyph symbols from Mount Bego rock art site achieving a classification rate of 68%
Towards a New Approach to Query Search Engines: The Search Tree Visual Language
No full textIn this paper, we describe the Search Tree visual language. It is a novel methodology able to support
users to build up complex queries to be run on given search engines. For using this visual language,
neither parentheses nor precedence rules are needed, nor the specific ability to perform advanced search
tasks. The language is proven to have the same expressive power as the expressions in Sum Of Product
form. In order to prove the appropriateness of our proposal, we measured the usability of the proposed
querying approach against the traditional YahooTM web search query language. Results show that, even if
both the approaches fully support users in terms of efficacy, the Search Tree visual language significantly
improves task efficiency, both in terms of the number of actions performed and the time requested with
respect to the advanced search interface
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