Worksheet for Last Exam 2000
Advanced Vector Geomatics
AKA Advanced Vector GIS



Define tessellation and provide at least three examples (e.g. demographic zones) of (a) irregular tessellations and (b) regular tessellations

How are lattices like tessellations and how are they different?

Consider the graphic on page 238 (fig 6.13) be prepared to create either the quad tree (open and blackened squares) or the "map" if you are given either the map or the tree.

Consider a similar taks for the material prvided in Figure 6.15 (page 240)

What is a TIN?

After a process of polygon overlay there may be "slivers" - what are the proceedures that could be applied to determine if the silvers should be eliminated by merging and how would you determine what polygon to merge them into?

What are the ten steps required to add a new element to a topological data structure?

Provide specific examples of the following ways to access spatial data:

    1. by name
    2. by singular position
    3. position that is relative to a reference system
    4. by a specific block of space
 In words, describe the general process of creating a network data strucutre in Arc 8. Discuss loads, impedances, demand, centers, stops etc. Draw a simple graphic that illustrates your points.
 

Why are bounding boxes often associated with each irregular polygon in a spatial data structure?
 

What are the strengths and weaknesses of the use of map tiles to organize spatial data?

 Discuss the strengths and weaknesses of the relational data base structure versus the object relational to store (1) spatial data and (2) attribute data. Historically why has the relational structure been used for attribute data and not as much for spatial data and why is the O-RDBMs gaining such wide interest?

What is conflation (when used in spatial operations) why is it used and provide an example.

 Why is strict planar enforcement not appropriate in the spatial structures which model transportation or other flows? 

 What are two spatial examples of the mathematical principle for the Dirichlet domain?

When we consider the very basic ways in which spatial data can be structure in a system one approach is to create structures (themes or coverages) that contain all the spatial elements (e.g. roads, parcels). Often times, however, the same spatial element (e.g. an edge) can be in two different themes. An edge of a parcel may be a street. Thus another approach is to store the elements and create a database that allows the theme to be created when needed. What are the strengths and weaknesses of these two approaches?

What are the types of impedances that can exist in a transportation network?

Why is it common to use dyadic structure when doing transportation modeling, what are some dyadic examples that can be used.
 

Using the below table normalize the structure, be sure to indicate the join columns.

Parcel Parcel address Owner’s Name Owners Address Date Assessed Building Type Number of Floors

123        234 Smith        St John Johnes     45 Main                      1995                   Brick store                      4

123        234 Smith St             "                               "                             "                    Frame house                     1

234          768 Jones           Mr Smith            67 Back                        1996                  Brick House                     1

234                "                    Mr Brown            245 Over                          "                         "                                  ‘

etc……
 

Provide a schema for the above normalized structure
 

Given the following data create an entity relationship for the spatial data and attribute data which includes owner(s) name, parcel id and the building(s) on each parcel

For the above create a set of tables that reflect the relationships that you have defined and populate them with two or three (simulated) lines of data.
 

There are a series of well known steps that are used to go from the "real world" to a Arc 8 database structure. Describe these steps and what are the essential operations that occur at each.

Provide one example of the type of operation/property that is permitted for the following transformations: (1) equi-area (2) similarity (3) affine (4) projective and (5) topological. Also provide one "real" example of the transformation as it is applied.

What do the relationship terms one to one, one to many and many to many describe? Provide at least two examples for each type of relationship.

Many transportation data structures use mile posts to record data and have very complex attributes that change at various points. How does this present a problem for a "standard" topological structure and how has it been addressed?

In the general case how can a system determine if two lines intersect?

L&T note that the storage of lines in the common form x = a + by doesn’t work well for spatial data and that suggest a parameterized expression. What is the parameterized expression and why is its use necessary?

Describe (in words) how the half line theorem is used.

What are the various methods that can be used to interpolate between two sets of polygons that cover the same location but are not coincident or nest-able.

What is the sequence of operations necessary to perform a polygon overlay operation?

Generally most GIS software either enforce topology as data are developed/digitized OR they do not require that topology be present until topological operations are needed. Discuss the positives/negatives of these two alternative ways to treat topology.

In words, describe in general how a generic software solves a classic allocation problem, schools and students. Assume that (1) you have student addresses (2) school location and capacity and (3) basic transportation data.

Districts can be composed through transportation network analysis using address data or through polygon "combinations" when the data are organized in that structure. Describe (in general terms) how these two different district formation approaches work.