420,948 research outputs found

    A Scalable Tile Map Service for Distributing Dynamic Choropleth Maps

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    In this paper we propose a solution to several key limitations of current web based mapping systems: slow rendering speeds and the restriction of online map viewing to a small number of areal units as well as a limited number of users. Our approach is implemented as a Scalable Tile Map Service that distributes dynamic choropleth maps in real-time through a new caching methodology. This new Map Service lays the foundation for advances in web based applications reliant on dynamic map rendering such as emergency management systems and interactive exploratory spatial data analysis. We present the results of an empirical illustration in which this new methodology is used to facilitate collaborative decision making by visualizing spatial outcomes of simulation results on the fly.

    Novel Decision Support Systems: Design and Assessment

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    This dissertation consists of three essays that propose designs and theoretically-based evaluations of two novel decision support systems (DSS): a web-based spatial DSS (SDSS), a dialectic DSS (DDSS), and a comparative analysis of subjective and objective measures of system success in terms of decision process and outcome. In the first essay, a web-based SDSS that utilizes the latest advances in web-based geographic information systems (GIS) is designed and developed to support decision makers for making spatial decisions. Task-technology, goal setting, and self-efficacy theories are synthesized to develop a conceptual model to explore the perceptual factors impacting the perceived performance of web-based SDSS. Building on the first essay’s theoretical model, a conceptual model for the second essay is developed for evaluating the efficacy of the proposed web-based DDSS that embeds a dialectic technique for unstructured problems, in order to elicit the underlying assumptions in the decision process. The third essay uses the research data from the prior essays to examine whether there is a discrepancy between subjective measures and objective measures of information-system success factors in the context of SDSS and DDSS. Together, these three essays extend the field by adding spatial and critical-thinking dimensions to the existing DSS and may provide a deeper understanding of perceptual and objective success measures for such systems

    APPLICATION OF WEBGIS-BASED SPATIAL DATA INVENTORY

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    The main purpose of this study was to establish an inventory application based on Web GIS spatial data that facilitated the user to manage spatial data in an integrated way. The method used in the development of the system was waterfall model of SDLC (System Development Life Cycle). Modeling systems analysis and design used to UML (Unified Modeling Language). The results of the analysis and design of the system implemented through language PHP (Hypertext Processor) and MySQL (My Structured Query Language). This software had the ability to extract digital data in GML (Geographic Markup Language)format, store spatial data in a WKT (Well-Known Text) format, and present spatial data in vector format that completed by legend and some facilities, such as: zoom in , zoom out, zoom to max extent, layer switcher, scale, scale line, mouse position, drawing tools, and a popup window. Based testing had been done; the system could handle spatial data management which included: storage and presentation of spatial data in vector format

    Segmentation-free inference of cell types from in situ transcriptomics data

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    Recent advances in the fields of genome editing, whole-genome sequencing, single-cell RNA sequencing, and in situ spatial transcriptomics have enabled the cost-efficient production of high-throughput big data. However, the lack of dedicated bioinformatics algorithms to analyze such data has been a big hurdle. In this thesis, several novel bioinformatics tools applicable to each field are presented. First, a series of web-based tools for genome editing are presented: Cpf1-Database, Cas-Analyzer, web-based Digenome-seq software, BE-Designer/Analyzer. These tools have been developed to guide researchers to easily use genome editing systems, using Cas9 or Cpf1, by providing an easily accessible web-based interface. Second, the development of two bioinformatics pipelines are described: a small variant calling pipeline to process tumor genome sequencing data without a matched control, and a pipeline to pre-process single-cell RNA sequencing data. Third, a novel segmentation-free algorithm to call cell-types from in situ transcriptomics data, namely Spot-based Spatial cell-type Analysis by Multidimensional mRNA density estimation (SSAM) is presented. Recent advances of in situ spatial transcriptomics techniques, such as multiplexed fluorescence in situ hybridization or in situ/intact tissue sequencing have enabled the discovery of spatial heterogeneity of cell types at the tissue level. However, cell type calling methods are often limited by cell segmentation algorithms due to various imaging problems. SSAM circumvents these problems by estimating spatial gene expressions as a density estimation of the mRNA in a spatial context and identifying de novo cell-types and their spatial organization without the need to segment cells. Optionally, SSAM can be guided by external sources of cell-type information, integrating them in a spatial context. In this thesis, SSAM is demonstrated with three different mouse brain tissues imaged by different imaging techniques: the somatosensory cortex (SSp) imaged by osmFISH; the hypothalamic preoptic region (POA) by MERFISH; and the visual cortex (VISp) by multiplexed smFISH. SSAM can produce similar results compared to segmentation-based methods and outperforms them when cell segmentation is the limiting factor. In summary, the bioinformatics tools presented in this thesis overcome major obstacles that would normally hinder effective analysis: the web-based tools for genome editing have a wide user base due to their easy-to-use web-based interfaces; omics data analysis pipeline that enables fast analysis of omics data utilizing a compute cluster and facilitate hypothesis generation when lacking control tissue; and SSAM that enables the analysis of in situ spatial transcriptomics data without being limited by cell segmentation. All of the tools and pipelines described in this thesis are open-sourced and freely accessible for non-profit, research-purpose use

    GIS-based Decision Support System (DSS) for Recommending Retail Outlet Locations

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    Many Information Technology (IT) tools play a vital role in the business world due to their wider applicability. Extremely competitive retail environment necessitates retailers to choose new store locations strategically. GIS with its capability to manage, display and analyze business information spatially, is emerging as one of the powerful location intelligence IT tool.  The purpose of this paper is to explore the possibility of strategic retail outlet location through online Decision Support System (DSS) in Hyderabad Metropolitan city, India. The procedure makes use of data, information and software from Web-based Geographical Information Systems (GIS) to generate online analysis, mapping and visualization systems. These procedures are integrated and synchronized with appropriate data layers (multi data layer system) to arrive at better decisions.  This DSS combines different data layers through spatial methodological analysis to arrive at possible solution for ideal retail store location. Keywords: Retail store site selection; spatial data layers; open source web GIS; DSS

    Assembly and concept of a web-based GIS within the paleolimnological project CONTINENT (Lake Baikal, Russia)

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    Web-based Geographical Information Systems (GIS) are excellent tools within interdisciplinary and multi-national geoscience projects to exchange and visualize project data. The web-based GIS presented in this paper was designed for the paleolimnological project 'High-resolution CONTINENTal paleoclimate record in Lake Baikal' (CONTINENT) (Lake Baikal, Siberia, Russia) to allow the interactive handling of spatial data. The GIS database combines project data (core positions, sample positions, thematic maps) with auxiliary spatial data sets that were downloaded from freely available data sources on the world wide web. The reliability of the external data was evaluated and suitable new spatial datasets were processed according to the scientific questions of the project. GIS analysis of the data was used to assist studies on sediment provenance in Lake Baikal, or to help answer questions such as whether the visualization of present-day vegetation distribution and pollen distribution supports the conclusions derived from palynological analyses. The refined geodata are returned back to the scientific community by using online data publication portals. Data were made citeable by assigning persistent identifiers (DOI) and were published through the German National Library for Science and Technology (TIB Hannover, Hannover, Germany).Continen
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