Geospatial computing in civil engineering

1
(Geospatial) computing in civil engineering

• Ari Jolma
• 12.4.2007

2
Materials

• Miles Ho 1999 Applications and Issues of GIS
  as Tool for Civil Engineering Modeling.
  J.Comp.Civ.Eng. Volume 13, Issue 3, pp. 144-152
• Venigalla Casey 2006 Innovations in Geographic
  Information Systems Applications for Civil
  Engineering. J.Comp.Civ.Eng. Volume 20, Issue 6,
  pp. 375-376
• Wikipedia pages GIS, CAD, Building Information
  Modeling, ...
• Peachavanish et al 2006 An ontological
  engineering approach for integrating CAD and GIS
  in support of infrastructure management. Advanced
  Engineering Informatics 20 (2006) 7188

3
Civil engineering

• a broad field of engineering dealing with the
  planning, construction, and maintenance of fixed
  structures, or public works, as they are related
  to earth, water, or civilization and their
  processes
• Fundamentally, we as civil engineersregardless
  of emphasis share one characteristic in that we
  are all problem solvers.

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Problem solving cycle

• Definition
• Structuring
• Defining possible solutions
• Evaluation of solutions
• Decision making
• Implementation

Modeling
Design
Simulation, optimization
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What are problems?

• G Polya How to solve it (from M Jackson
  Software requirements and specifications)
• ideas for solving mathematical problems
• from ancient Greeks
• the first people in Western world to think
  systematically about how to solve problems
• (1) problems to prove, (2) problems to find
• Each problem has principal parts and a solution
  task
• (1) parts are hypothesis and conclusion
• (2) parts are unknown, the data, and the
  condition
• Fitting a problem into a particular frame is a
  primary activity in understanding any problem

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Domain characteristics

• The characteristics of the (CE) context of the
  problem
• Characteristics of the data and information that
  the CE professional has to manage computationally
• Tangible vs intangible
• Dynamic vs static
• Spatial vs aspatial
• ...

7
Design cycle

• Conceive (innovate)
• Design
• Develop
• Build / manufacture
• Operate / maintain

Model
Drawings
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A design is a solution

• A CE design may be
• a structure
• a plan
• which may include also structures
• a management procedure
• an operational procedure

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Computing

• Manage acquired data and information
• that is from outside sources
• that is made within the project / organization
• Produce required/useful data and information
  products
• to match generic methods
• to match specific needs of people

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GIS

• Geospatial software
• Varying origins/foci
• Cartography
• One or more methods
• Resource management
• Management of geospatial data

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Brief history of GIS 1

• 60s
• Tomlinson CGIS
• land-use management, resource monitoring
• Laboratory for Computer Graphics and Spatial
  Analysis at the Harvard Graduate School of Design
  
• 70s
• Commercial mapping applications sold by vendors
• 80s
• Personal computer interaction, new application
  areas

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Brief history of GIS 2

• 90s
• Tomlin cartographic modeling
• GIS and hydrological modeling
• Increasing commercialization
• 2000
• Web, spatial data infrastructures

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GIS and CE 1

• Benefits
• Capture, store, and manage geospatially
  referenced data in common formats
• Visualization capabilities for information and
  verification
• Common methods to compute information from
  Digital Elevation Models (DEM)

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GIS and CE 2

• Problem areas
• The mismatch between CE specifics and generic GIS
  capabilities
• The common GIS data model is generic and simple
  -gt difficulties in applying CE specific data
  models
• Linking of CE (simulation) models with GIS that
  lack the concept of temporal data

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The GIS data model

• Thematic layers
• Features sharing a similar set of attributes
• feature spatial object record of attributes
• Common spatial representations
• points, polylines, polygons, rasters
• Topological relationships
• it is common to not to specify these explicitly

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A CE data model (an example water management
plan)

• Hydro system description and operation
• objectives flood control, storage, ecology, ...
• Monitoring system and operation
• Loads and associated permits and requirements
  etc.
• Other actions and measures

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CAD

• A computer-based design tool
• Commonly used, e.g., in Architecture,
  Engineering, and Construction
• for creating plans and drawings
• 2D drafting / 3D solid modeling

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The CAD data model

• A mathematical model for describing arbitrary
  (smooth) curves and surfaces
• Boundary representation
• topology (faces, edges, vertices) geometry
• compare to GIS data model!
• NURBS
• non uniform rational B-spline

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CE and CAD 1

• Benefits
• Create engineering drawings and visualizations
• Simulation of designs
• Output of design data to manufacturing utilities
• Maintain libraries of parts and assemblies

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CE and CAD 2

• Problem areas
• (If there is a) focus on drawings and not in the
  data model
• Interoperability problems, especially caused by
  proprietary file formats

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GML, LandXML, IFC, ...

• A shared data model is a key to interoperability
  that is an important requirement as CE projects
  are often large and involve many participants
• Data and information exchange
• between organizations
• between planning tools and equipment
• Based on
• XML (Extensible mark-up language)
• Object-orientation
• Ontologies

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Data in an information system

• Organized structure (data model)
• Efficient update and querying
• also complex updates and queries
• standards-based update and querying
• employs advanced algorithms!
• Remove redundancy
• within one data base
• within organization
• A single shared/forced structure
• Management objectives
• security, integrity, ...
• Support discovery

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State-of the art solutions

• RDBMS
• relational database management systems
• data is in tables, tables have columns (fields)
  and rows (tuples), columns have a field name,
  field data type, ...
• columns between tables may be linked
• SQL
• structured query language
• OODBMS
• Object-oriented database management systems
• data is stored as objects, objects have a class,
  a class has attributes and methods, attributes
  have names and data types
• classes may have various types of relationships

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Data in messages

• Messages are a means of communication
• In computing
• humanlt-gthuman (not directly, via a computer
  system)
• human-gtprogram
• program-gthuman
• programlt-gtprogram
• Semantics
• Syntax
• construction of complex signs from simpler signs
• Pragmatics
• how signs are interpreted in particular
  circumstances or context

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State-of-the-art computational solutions

• Derivatives of SGML
• standard generalized markup language
• HTML, XML
• Typesetting and document formats
• LaTeX, .doc, RTF, ...
• All other file formats
• Shapefile, DGW
• All program to program protocols
• ODBC (open database connectivity), ...
• Everything else
• SQL, ...

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Digging still deeper...

• Descriptions
• raw material for databases
• raw material for message structures
• raw material for problem solving
• raw material for program development
• The suitability of a description is judged by the
  purpose
• Descriptions are organized thoughts
• the level of organization may vary
• Descriptions are not specifications

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State-of-the-art solutions

• Predicate logic
• extension of propositional logic
• logic with generalized facts
• Jackson designations, definitions, refutable
  descriptions, rough sketches
• Ontologies
• a data model that represents a set of concepts
  within a domain and the relationships between
  those concepts
• UML
• a standardized specification language for object
  modeling
• structure, behavior, and interaction diagrams
• really a specification language

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The basic solution of/for a poor man 1

• There are objects, and they are realisations of
  classes
• An example of a class a wetland
• Classes have attributes and characteristics
• For exampe average depth
• For example a wetland designed primarily for
  birds, a wetland for designed primarily for
  water quality improvement
• Classes have relationships
• For example a wetland is on a property, a
  wetland has a catchment
• When some description is an attribute and when it
  is a relationship is a design choice

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The basic solution of/for a poor man 2

• There are processes
• For example a wetland is planned and built and
  then it is in operation

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Ontologies (knowledge engineering)

• Classes (concepts)
• a set of objects
• compare to an idea of an object
• a subset subsume, inherit, is a kind of
• e.g. vehicle -gt car
• Attributes of classes
• name, value
• Relationships between classes
• inheritance, a part of, ...

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Object-orientation (software development)

• A program is a collection of cooperating objects
• cooperation is ideally based on communication
  with messages
• Classes, attributes, methods
• Inheritance, encapsulation, abstraction,
  polymorphism
• The methods constitute the primary interface of
  an object, its data is encapsulated within the
  object. Methods may be inherited from
  superclasses and the behavior they awake may be
  different, giving raise to polymorphism.

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XML (information system design)

• A tree-like stucture of nodes
• each node has possibly a parent, children,
  siblings (the siblings form a list)
• a node consists of contents that is surrounded by
  begin and end tags, in the begin tag there may be
  named attributes with values
• lttag attr1valuegtcontentslt/taggt