129 research outputs found

    Mobile Geographic Information Systems

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    This Chapter introduces the concept of Mobile Geographical Information Systems (Mobile GIS) as an evolution of conventional GIS to being available on wireless mobile devices such as smart phones. The evolution of the technology and its applications are charted in this Chapter. The main elements of Mobile GIS are then discussed. This focuses on: GIS servers; wireless mobile telecommunication networks; wireless mobile devices; location-awareness technology; and gateway services. This is followed by a discussion of the main features in terms of the services and usage of Mobile GIS: mobility; real-time connectivity; location-awareness; broadened usage. Mobile GIS are an important facilitating technology for Location-Based Services (LBS). A range of applications of Mobile GIS for smart phones are described. The Chapter closes with a discussion of the prospects and challenges for Mobile GIS. Challenges derive from four broad areas: limitations that derive from the technologies being used; areas of GIScience that still need to be adequately researched; users; and business models for a sustainable presence

    Mobile Geographic Information Systems (GIS) for Humanitarian Demining

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    The threat of landmines and other explosive remnants of war is a serious concern around the world. While landmines demand attention due to the thousands of civilian casualties they cause each year, perhaps even more shocking is the fear they instill in local populations, inhibiting movement and denying access to thousands of square kilometers of land in more than 80 countries. Humanitarian demining seeks to rid the world of landmines and return local populations to their displaced land. To meet this goal, surveys of hazardous areas, describing their location and contents, are used to produce threat maps for a given location and secure adequate funding from donor organizations for clearance operations. The focus of this study is a mobile GIS system, developed by the Geneva International Centre for Humanitarian Demining (GICHD), which allows rapid, accurate, and completely digital collection of these demining surveys. Using data collected during local evaluations of the demining Survey Tool at the University of Kansas campus and on foreign field deployments in Chile (2004), Albania (2004), Ecuador (2004), and Lebanon (2006), a fit-for-use analysis was performed on each component of the Survey Tool. Experiments were conducted to evaluate the accuracy of its GPS and laser rangefinder mapping devices, and methods for improving that accuracy were investigated. The system was well received by all of its users and gauged to be twice as fast, require half the personnel, and provide higher levels of accuracy than traditional methods for collecting demining surveys. Even though the system was deemed fit for use, suggestions for improving all components of the device resulted from user feedback and observations of the system in the field. The system's GPS receiver was predicted to provide 5 m accuracy 50 % of the time and 10 m accuracy 95 % of the time. If GPS positions were averaged for 1 minute, the 95% accuracy improved to 7.5 m, and if positions were averaged for 4 minutes, the 95% accuracy improved to 5.6 m. The two types of laser rangefinders used by the system were found to have a mean accuracy of 2.7 m when shooting at a location on the horizontal bare earth and a mean accuracy of 1.1 m when shooting at a well defined vertical target. Rangefinder accuracy varied due to level of user experience with rangefinders or other sighting equipment, and thus proved the value of training with these devices. Also, significant errors in bearing measurements with the rangefinders caused by magnetic interference from one user's eye glasses indicated that this issue requires considerable attention by all users of laser rangefinder devices. General themes that were found to be extremely important to the success of the demining system, such as the value of training, the need for system flexibility to match traditional field methods, and the complexities of GIS data collection in the field, should be a focus of any mobile GIS field program

    An Egocentric Spatial Data Model for Intelligent Mobile Geographic Information Systems

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    Individuals in unknown locations, such as utility workers in the field, soldiers on a mission, or sightseeing tourists, share the need for an answer to two basic questions: Where am I? and What is in front of me?Because such information is not readily available in foreign locations, aids in the form of paper maps or mobile GISs, which give individuals an all-inclusive view of the environment, are often used. This panoptic view may hinder the positioning and orienteering process, since people perceive their surroundings perspectively from their current position. In this thesis, I describe a novel framework that resolves this problem by applying sensors that gather the individual\u27s spatial frame of reference. This spatial frame of reference, in combination with an egocentric spatial data model enables an injective mapping between the real world and the data frame of reference, hence, alleviating the individual\u27s cognitive workload. Furthermore, our egocentric spatial data model allows intelligent mobile Geographic Information Systems to capture the notions of here and there, and, consequently, provides insight into the individual\u27s surroundings. Finally, our framework, in conjunction with the context given by the task to be performed, enables intelligent mobile Geographic Information Systems to implicitly answer questions with respect to where, what, and how

    Using Mobile Geographic Information Systems to Improve Operational Efficiency, Data Reliability, and Access in Mine Action

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    The inherently complex field of mine action, with its many political, financial, and physical considerations, is also a spatial, data-driven field; and as a result, geographic information systems (GIS) stand to play a major role. Spatial data can help address questions such as: Where are the hazardous areas and what has been cleared or cancelled? Where have teams already surveyed? Where should they go next? How many square meters have been cleared? Due to the complexities surrounding assigning tasks and prioritization, standard operating procedures (SOP), quality assurance/quality control (QA/QC) and database design, GIS often gets limited to high-level planning, database cataloging, and end-of-task analysis and reporting. With the improvement of mobile technologies and locationbased services, GIS is poised to play a bigger role in the dayto-day operations of landmine and unexploded ordnance (UXO) clearance

    Investigating The Local Food System: A Mixed Methods Study Of Sustainability in Southwest Atlanta

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    Local food systems can play an important role in the environmental sustainability and human health of communities. This study aims to evaluate connections between the local food system and the retail environment in Southwest Atlanta, Georgia (USA) through mixed methods research. Agriculture site interviews and field research evaluate issues surrounding the local food system from a qualitative perspective. A mobile Geographic Information Systems (GIS) framework is developed to evaluate access and disparities in the retail food landscape from a quantitative perspective. This framework can be leveraged by residents and community stakeholders towards strategic primary data and research needs. In using both qualitative and quantitative methods, a more comprehensive study of the local food system and overall sustainability of communities is enabled. The results of this study may better inform planning and policy decisions and serve as a research model for use in other geographies

    Mobile Geographic Information System as a tool to help collect data on telecommunications network

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    This thesis describes the procedure of data collection and the setting up of a system for unified management and conservation of data on telecommunications infrastructure. The reasons and the purpose of setting up a common database in the company Telekom Slovenije d.d. are specified in this thesis as well as the problem of the outstanding documentation and the collection of these documentation in the field using mobile geographic information systems. A test data collection using a handheld GPS receiver MobileMapper CX was carried out within the functional location (FL) 1158 Gradišče nad Pijavo Gorico

    Continuous Representation of Location for Geolocation and Lexical Dialectology using Mixture Density Networks

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    We propose a method for embedding two-dimensional locations in a continuous vector space using a neural network-based model incorporating mixtures of Gaussian distributions, presenting two model variants for text-based geolocation and lexical dialectology. Evaluated over Twitter data, the proposed model outperforms conventional regression-based geolocation and provides a better estimate of uncertainty. We also show the effectiveness of the representation for predicting words from location in lexical dialectology, and evaluate it using the DARE dataset.Comment: Conference on Empirical Methods in Natural Language Processing (EMNLP 2017) September 2017, Copenhagen, Denmar
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