2020 QUARTER 03

A B C D E F G H I J K L M N O P R S T U V W

DM-15 - The network model

Define the following terms pertaining to a network: Loops, multiple edges, the degree of a vertex, walk, trail, path, cycle, fundamental cycle
List definitions of networks that apply to specific applications or industries
Create an adjacency table from a sample network
Explain how a graph can be written as an adjacency matrix and how this can be used to calculate topological shortest paths in the graph
Create an incidence matrix from a sample network
Explain how a graph (network) may be directed or undirected
Demonstrate how attributes of networks can be used to represent cost, time, distance, or many other measures
Demonstrate how the star (or forward star) data structure, which is often employed when digitally storing network information, violates relational normal form, but allows for much faster search and retrieval in network databases
Discuss some of the difficulties of applying the standard process-pattern concept to lines and networks
Demonstrate how a network is a connected set of edges and vertices

FC-20 - The power of maps

Describe how maps such as topographic maps are produced within certain relations of power and knowledge
Discuss how the choices used in the design of a road map will influence the experience visitors may have of the area
Explain how legal issues impact the design and content of such special purpose maps as subdivision plans, nautical charts, and cadastral maps
Exemplify maps that illustrate the provocative, propagandistic, political, and persuasive nature of maps and geospatial data
Demonstrate how different methods of data classification for a single dataset can produce maps that will be interpreted very differently by the user
Deconstruct the silences (feature omissions) on a map of a personally well known area
Construct two maps about a conflict or war producing one supportive of each side’s viewpoint

KE-01 - The process of GIS&T design

Describe the major approaches to the design of geospatial systems
Analyze past cases to identify best practices of design and implementation
Compare and contrast the relative merits of the use-case driven and architecture-centric design processes

The raster data model is a widely used method of storing geographic data. The model most commonly takes the form of a grid-like structure that holds values at regularly spaced intervals over the extent of the raster. Rasters are especially well suited for storing continuous data such as temperature and elevation values, but can hold discrete and categorical data such as land use as well. The resolution of a raster is given in linear units (e.g., meters) or angular units (e.g., one arc second) and defines the extent along one side of the grid cell. High (or fine) resolution rasters have comparatively closer spacing and more grid cells than low (or coarse) resolution rasters, and require relatively more memory to store. Active research in the domain is oriented toward improving compression schemes and implementation for alternative cell shapes (such as hexagons), and better supporting multi-resolution raster storage and analysis functions.

DM-12 - The spaghetti model

Identify a widely-used example of the spaghetti model (e.g., AutoCAD DWF, ESRI shapefile)
Write a program to read and write a vector data file using a common published format
Explain the conditions under which the spaghetti model is useful
Explain how the spaghetti data model embodies an object-based view of the world
Describe how geometric primitives are implemented in the spaghetti model as independent objects without topology

DM-13 - The topological model

Define terms related to topology (e.g., adjacency, connectivity, overlap, intersect, logical consistency)
Describe the integrity constraints of integrated topological models (e.g., POLYVRT)
Discuss the historical roots of the Census Bureau’s creation of GBF/DIME as the foundation for the development of topological data structures
Explain why integrated topological models have lost favor in commercial GIS software
Evaluate the positive and negative impacts of the shift from integrated topological models
Discuss the role of graph theory in topological structures
Exemplify the concept of planar enforcement (e.g., TIN triangles)
Demonstrate how a topological structure can be represented in a relational database structure
Explain the advantages and disadvantages of topological data models
Illustrate a topological relation

DM-10 - The Triangulated Irregular Network (TIN) model

Describe how to generate a unique TIN solution using Delaunay triangulation
Describe the architecture of the TIN model
Construct a TIN manually from a set of spot elevations
Delineate a set of break lines that improve the accuracy of a TIN
Describe the conditions under which a TIN might be more practical than GRID
Demonstrate the use of the TIN model for different statistical surfaces (e.g., terrain elevation, population density, disease incidence) in a GIS software application

FC-27 - Thematic Accuracy Assessment

Geographic Information System (GIS) applications often involve various analytical techniques and geographic data to produce thematic maps for gaining a better understanding of geospatial situations to support spatial decisions. Accuracy assessment of a thematic map is necessary for evaluating the quality of the research results and ensuring appropriate use of the geographic data. Thematic accuracy deals with evaluating the accuracy of the attributes or labels of mapped features by comparing them to a reference that is assumed to be true. The fundamental practice presents the remote sensing approach to thematic accuracy assessment as a good guidance. For instance, the accuracy of a remote sensing image can be represented as an error matrix when the map and reference classification are conducted based on categories. This entry introduces basic concepts and techniques used in conducting thematic accuracy with an emphasis on land cover classification based on remote sensing images. The entry first introduces concepts of spatial uncertainty and spatial data quality standards and further gives an example of how spatial data quality affects thematic accuracy. Additionally, the entry illustrates the techniques that can be used to access thematic accuracy as well as using spatial autocorrelation in thematic accuracy sampling design.

AM-86 - Theory of error propagation

Describe stochastic error models
Exemplify stochastic error models used in GIScience

FC-08 - Time

Time is a fundamental concept in geography and many other disciplines. This article introduces time at three levels. At the philosophical level, the article reviews various notions on the nature of time from early mythology to modern science and reveals the dual nature of reality: external (absolute, physical) and internal (perceived, cognitive). At the analytical level, it introduces the measurement of time, the two frames of temporal reference: calendar time and clock time, and the standard time for use globally. The article continues to discuss time in GIS at the practical level. The GISystem was first created as a “static” computer-based system that stores the present status of a dynamic system. Now, GISystems can track and model the dynamics in geographical phenomena and human-environment interactions. Representations of time in dynamic GISystems adopt three perspectives: discrete time, continuous time and Minkowski’s spacetime, and three representations: ordinal, interval, and cyclical. The appropriate perspective and representation depend on the observed temporal patterns, which can be static, oscillating, chaotic, or stochastic. Recent progress in digital technology brings us opportunities and challenges to collect, manage and analyze spatio-temporal data to advance our understanding of dynamical phenomena.