Papers by Francesc Castro
Spatial and dynamic data modeling and simulation Image processing Bioinformatics Voronoi ... more Spatial and dynamic data modeling and simulation Image processing Bioinformatics Voronoi arts Other Applications 2. Other theoretical aspects and applications of geometric computing and design. Authors are invited to submit papers (up to 10 pages) describing original research works related to the following topics: 1. Theory and applications of Voronoi diagrams and Delaunay triangulation. Theoretical aspects of Voronoi diagrams and Delaunay triangulations Generalizations of Voronoi diagrams and Delaunay triangulations Computational algorithms and implementation aspects of Voronoi diagrams And the applications of Voronoi diagrams in Visualization, animation and motion planning Pattern analysis and recognition Topics of Interest June 28-30, 2011 Qingdao, China The 8th ISVD International Symposium on Voronoi Diagrams in Science and Engineering is devoted to the research on the Voronoi diagram and its application to all fields. The conference provides a forum for scientists and practitioners working on Voronoi Diagrams and on their applications in science and engineering including, geo-spatial information sciences (GIS), visualization, urban planning, computer science, geology, robotics, bioinformatics, highperformance computing, bioinformatics, physics, chemistry and other applications. We solicit original research contributions and industrial papers.
The Visual Computer, May 1, 2001
In this paper, we explore image reconstruction by natural neighbour interpolation from irregularl... more In this paper, we explore image reconstruction by natural neighbour interpolation from irregularly spaced samples. We sample the image irregularly with techniques based on the Laplacian or the derivative in the direction of the gradient. Local coordinates based on the Voronoi diagram are used in natural neighbour interpolation to quantify the "neighbourliness" of data sites. Then we use natural neighbour interpolation in order to reconstruct the image. The main result is that the image quality is always very good in the case of the sampling techniques based on the Laplacian.
Ecology and the Environment, Jul 1, 2015
In this paper the methods for data processing and online mapping of the pollution with heavy meta... more In this paper the methods for data processing and online mapping of the pollution with heavy metals caused by mining in New Brunswick, Canada will be presented. The mining in New Brunswick is mostly done in uninhabited areas so it does not affect the population living in the cities. However, the remote communities of First Nations often find that the mining activities affect their sources of water and food, especially wild game. In this project funded by Health Canada the research was done to investigate the sources of the pollution related to the mining activities and to develop mapping techniques that will allow evaluation of the risk of the pollution to the remote communities.
Springer eBooks, 2009
A spatial component for health data can support spatial analysis and visualization in the investi... more A spatial component for health data can support spatial analysis and visualization in the investigation of health phenomena. Therefore, the utilization of spatial information in a Semantic Web environment will enhance the ability to query and to represent health data. In this paper, a semantic health data query and representation framework is proposed through the formalization of spatial information. We include the geometric representation in RuleML deduction, and apply ontologies and rules for querying and representing health information. Corresponding geospatial built-ins were implemented as an extension to OO jDREW. Case studies were carried out using geospatialenabled RuleML queries for respiratory disease information. The paper thus demonstrates the use of RuleML for geospatial-semantic querying and representing of health information.
European Workshop on Computational Geometry, 2000
Construction and Building Materials, Nov 1, 2019
The present study investigates the use of close-range photogrammetry for automated air void analy... more The present study investigates the use of close-range photogrammetry for automated air void analysis of hardened concrete without contrast enhancement. First, polished plane sections of concrete with varying air contents were analyzed by photogrammetry. The data in the form of point clouds were processed to identify the air voids. Second, the same plane sections were subjected to traditional air void analysis by contrast enhancement. Results of both methods were compared. The method based on photogrammetry showed potential, but it could not capture the smallest air voids. Better camera resolution and/or methods to reduce noise in the point cloud are needed.
Springer eBooks, Jul 15, 2008
Flooding has been one of the most costly disasters in terms of property damage and human casualti... more Flooding has been one of the most costly disasters in terms of property damage and human casualties. The damage to the infrastructure can also be extensive, and it can endanger flood evacuation efforts. During flooding, emergency managers need to know which evacuation route is safe for their vehicles. In evacuation planning, knowing the water depths on roads and taking into
The calculation of the overlap volume of halfspheres or ellipsoids is of direct interest in struc... more The calculation of the overlap volume of halfspheres or ellipsoids is of direct interest in structural bioinformatics, which is concerned with the computational study of biological macromolecules on a genomic scale. We present an algorithm for computing the Delaunay graph and the overlap volume of a set of half-balls using exact predicates that detect the disjointness or non-disjointness of two half-balls and the validity of the generalized Voronoi vertex of four half-balls using geometric invariants and action (multiplication map) matrices. We prove the correctness of the algorithm and the optimality of the degree of the predicates by using geometric invariants and Gröbner bases. The main application of these certified computations is to predict the 3D structure of proteins.
Lecture Notes in Computer Science, 2010
ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Oct 19, 2015
Supply Chain Management (SCM) is the management of the products and goods flow from its origin po... more Supply Chain Management (SCM) is the management of the products and goods flow from its origin point to point of consumption. During the process of SCM, information and dataset gathered for this application is massive and complex. This is due to its several processes such as procurement, product development and commercialization, physical distribution, outsourcing and partnerships. For a practical application, SCM datasets need to be managed and maintained to serve a better service to its three main categories; distributor, customer and supplier. To manage these datasets, a structure of data constellation is used to accommodate the data into the spatial database. However, the situation in geospatial database creates few problems, for example the performance of the database deteriorate especially during the query operation. We strongly believe that a more practical hierarchical tree structure is required for efficient process of SCM. Besides that, three-dimensional approach is required for the management of SCM datasets since it involve with the multi-level location such as shop lots and residential apartments. 3D R-Tree has been increasingly used for 3D geospatial database management due to its simplicity and extendibility. However, it suffers from serious overlaps between nodes. In this paper, we proposed a partition-based clustering for the construction of a hierarchical tree structure. Several datasets are tested using the proposed method and the percentage of the overlapping nodes and volume coverage are computed and compared with the original 3D R-Tree and other practical approaches. The experiments demonstrated in this paper substantiated that the hierarchical structure of the proposed partitionbased clustering is capable of preserving minimal overlap and coverage. The query performance was tested using 300,000 points of a SCM dataset and the results are presented in this paper. This paper also discusses the outlook of the structure for future reference.
International Journal of Safety and Security Engineering, Sep 30, 2015
Populations are usually unprepared for natural disasters (even in regions of high risk), and emer... more Populations are usually unprepared for natural disasters (even in regions of high risk), and emergency planners are faced with the difficult task of evacuating these unprepared people quickly. Recent advances in Geographic Information Systems (GIS) technology allow for improved determination and mapping of risks for different natural and man-made disasters. Large amounts of data can be acquired, processed, analysed and displayed on digital maps, thus allowing the decision makers to assess the situation rapidly and take appropriate actions. Advanced hydrological tools for computation and modelling of natural hazards (such as floods) can be combined with GIS tools that have the capability of decision support and advanced visualization. This combination can be used to produce models that will represent the risks of natural and man-made disasters in the form of risk maps. Furthermore, these processes can be automated, which can allow for near real-time access to the risk maps. This can greatly help decision makers with emergency and mitigation measures, however the challenge is to design tools that meet the specific needs of emergency managers charged with the protection of a diverse and under-prepared populace. The research aimed to demonstrate the potential of GIS mapping tools with reference to two real case studies in Fredericton, New Brunswick, Canada. The first one relates to flood risk mapping needed for the evacuation of vulnerable populations, while in the second one, the mapping of a catastrophic flood scenario due to a dam break is presented. The results of both case studies has helped to identify that the evacuation of socially vulnerable sections of the population require more resources and emergency planning than the evacuation of the rest of population. The socially vulnerable population needs to be registered before the disaster occurs and their special needs need to be documented. The response time needed to evacuate people, especially those who are socially vulnerable is very important in saving lives. There exist a number of important factors when planning for an evacuation, e.g. the number of people to be evacuated, time available for the evacuations, the distance to travel and also the available routes for evacuation. The provisions of medicaments, special food and any additional resources have to be planned and prepared in advance. Here, the approach to identify, map and assist the evacuation of socially vulnerable population during flooding in Fredericton while taking care of their special needs is presented. The main result of this research is a web-based GIS system that provides appropriate information to the relevant authorities and general public in a timely manner and easy to understand.
This paper presents a methodology towards the emulation of the electrical power consumption of th... more This paper presents a methodology towards the emulation of the electrical power consumption of the RF device during the cellular phone/handset transmission mode using the LTE technology. The emulation methodology takes the physical environmental variables and the logical interface between the baseband and the RF system as inputs to compute the emulated power dissipation of the RF device. The emulated power, in between the measured points corresponding to the discrete values of the logical interface parameters is computed as a polynomial interpolation using polynomial basis functions. The evaluation of polynomial and spline curve fitting models showed a respective divergence (test error) of 8% and 0.02% from the physically measured power consumption. The precisions of the instruments used for the physical measurements have been modeled as intervals. We have been able to model the power consumption of the RF device operating at 5MHz using homotopy between 2 continuous power consumptio...
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The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012
Currently, addressing practices in Greenland do not support geocoding. Addressing points on a map... more Currently, addressing practices in Greenland do not support geocoding. Addressing points on a map by geographic coordinates is vital for emergency services such as police and ambulance for avoiding ambiguities in finding incident locations (Government of Greenland, 2010) Therefore, it is necessary to investigate the current addressing practices in Greenland. Asiaq (Asiaq, 2011) is a public enterprise of the Government of Greenland which holds three separate databases regards addressing and place references: • list of locality names (towns, villages, farms), • technical base maps (including road center lines not connected with names, and buildings), • the NIN registry (The Land Use Register of Greenland -holds information on the land allotments and buildings in Greenland). The main problem is that these data sets are not interconnected, thus making it impossible to address a point in a map with geographic coordinates in a standardized way. The possible solutions suffer from the fact that Greenland has a scattered habitation pattern and the generalization of the address assignment schema is a difficult task. A schema would be developed according to the characteristics of the settlement pattern, e.g. cities, remote locations and place names. The aim is to propose an ontology for a common postal address system for Greenland. The main part of the research is dedicated to the current system and user requirement engineering. This allowed us to design a conceptual database model which corresponds to the user requirements, and implement a small scale prototype. Furthermore, our research includes resemblance findings in Danish and Greenland's addressing practices, data dictionary for establishing Greenland addressing system's logical model and enhanced entity relationship diagram. This initial prototype of the Greenland addressing system could be used to evaluate and build the full architecture of the addressing information system for Greenland. Using software engineering methods the implementation can be done according to the developed data model and initial database prototype. Development of the Greenland addressing system using a modern GIS and database technology would ease the work and improve the quality of public services such as: postal delivery, emergency response, customer/business relationship management, administration of land, utility planning and maintenance and public statistical data analysis.
2006 3rd International Symposium on Voronoi Diagrams in Science and Engineering, 2006
This paper presents a methodology to automate some parts of the manual digitization process. This... more This paper presents a methodology to automate some parts of the manual digitization process. This includes replacing the manual digitization process by computer assisted skeletonization using scanned paper maps. In colour scanned paper maps various features on the map can be distinguished based on their colour. This research work utilizes the Delaunay triangulation and the Voronoi diagram in order to
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Papers by Francesc Castro