(geospatial) computing in civil engineering
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(Geospatial) computing in civil engineering. Ari Jolma 12.4.2007. 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 - PowerPoint PPT PresentationTRANSCRIPT
(Geospatial) computing in civil engineering
Ari Jolma12.4.2007
Materials
Miles & Ho 1999: Applications and Issues of GIS as Tool for Civil Engineering Modeling. J.Comp.Civ.Eng. Volume 13, Issue 3, pp. 144-152Venigalla & Casey 2006: Innovations in Geographic Information Systems Applications for Civil Engineering. J.Comp.Civ.Eng. Volume 20, Issue 6, pp. 375-376Wikipedia 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) 71–88
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 processesFundamentally, we as civil engineers—regardless of emphasis— share one characteristic in that we are all problem solvers.
Problem solving cycle
DefinitionStructuringDefining possible solutionsEvaluation of solutionsDecision makingImplementation
Design
Simulation,optimization
Modeling
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
Domain characteristics
The characteristics of the (CE) context of the problemCharacteristics of the data and information that the CE professional has to manage computationallyTangible vs intangibleDynamic vs staticSpatial vs aspatial...
Design cycle
Conceive (innovate)DesignDevelopBuild / manufactureOperate / maintain
Model
Drawings
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
Computing
1. Manage acquired data and information
that is from outside sources that is made within the project /
organization
2. Produce required/useful data and information products
to match generic methods to match specific needs of people
GIS
Geospatial softwareVarying origins/foci Cartography One or more methods Resource management Management of geospatial data
Brief history of GIS 1
60’s Tomlinson: CGIS
land-use management, resource monitoring Laboratory for Computer Graphics and Spatial
Analysis at the Harvard Graduate School of Design
70’s Commercial mapping applications sold by
vendors
80’s Personal computer: interaction, new application
areas
Brief history of GIS 2
90’s Tomlin: cartographic modeling GIS and hydrological modeling Increasing commercialization
2000 Web, spatial data infrastructures
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)
GIS and CE 2
Problem areas The mismatch between CE specifics
and generic GIS capabilities The common GIS data model is
generic and simple -> difficulties in applying CE specific data models
Linking of CE (simulation) models with GIS that lack the concept of temporal data
The GIS data model
Thematic layersFeatures 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
A CE data model (an example: water management plan)
Hydro system description and operation objectives: flood control, storage,
ecology, ...
Monitoring system and operationLoads and associated permits and requirements etc.Other actions and measures
CAD
A computer-based design toolCommonly used, e.g., in Architecture, Engineering, and Construction for creating plans and drawings
2D drafting / 3D solid modeling
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
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
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
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 participantsData and information exchange between organizations between planning tools and equipment
Based on XML (Extensible mark-up language) Object-orientation Ontologies
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
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
Data in messages
Messages are a means of communicationIn computing
human<->human (not directly, via a computer system)
human->program program->human program<->program
Semantics Syntax
construction of complex signs from simpler signs Pragmatics
how signs are interpreted in particular circumstances or context
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, ...
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 purposeDescriptions are organized thoughts the level of organization may vary
Descriptions are not specifications
State-of-the-art solutions
Predicate logic extension of propositional logic logic with generalized facts
Jackson: designations, definitions, refutable descriptions, rough sketchesOntologies
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
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
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”
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 -> car
Attributes of classes name, value
Relationships between classes inheritance, ”a part of”, ...
Object-orientation (software development)
A program is a collection of cooperating objects cooperation is ideally based on
communication with messagesClasses, attributes, methodsInheritance, encapsulation, abstraction, polymorphismThe 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.
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
<tag attr1=”value”>contents</tag>