ΕΘΝΙΚΟ ΜΕΤΣΟΒΙΟ ΠΟΛΥΤΕΧΝΕΙΟ ΕΜΠ Εργαστήριο Συγκοινωνιακής Τεχνικής Χρήση συστημάτων πληροφορικής στην οδική υποδομή Βύρωνας Νάκος Καθηγήτης ΕΜΠ bnakos@central.ntua.gr Δομή ενός Συστήματος Γεωγραφικών Πληροφοριών για Μεταφορές
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Συστήματα Γεωγραφικών Πληροφοριών & Μεταφορές Βύρωνας Νάκος, Καθηγητής Ε.Μ.Π. Δομή ενός Συστήματος Γεωγραφικών Πληροφοριών για Μεταφορές
Contents Components of a GIS-T Software interface Data entry & editing Spatial data manipulation Spatial data processing Spatial analysis (statistical analysis spatial operators shortest path analysis vehicle routing arc routing network flow models partitioning, clustering & regionalization location-allocation model)
Components of a GIS-T Hardware Software Transportation Spatial database
Cost investment ratio 1000 1 100 Hardware Software Data
Software interface Graphical user interface (GUI) Command line Scripts
Tools Python script Model Builder (ArcGIS)
Data entry & editing Manual digitization & scanning Data verification (error detection) Interactive or batch processing data correction Edge matching
Heads-up digitization
Data entry topological errors
Edge matching Rubber-sheet transformation
Spatial data manipulation Spatial data storage & retrieval Network topology (arc-node) Spatial queries Browsing facilities Data access & security Roll-back facilities Minimization of redundancy Database partitioning
Spatial data processing Data conversion (e.g. raster to vector) Map projection transformation Spatial classification Thematic classification Spatial simplification Spatial aggregation Generalization
Spatial analysis Statistical analysis Frequency analysis Dispersion measures Mean trend measures Spatial correlation Spatial regression
Spatial analysis Spatial operators Applied to objects: Length Area Boundary Box Extend Topological operators: Union Intersection Difference Separation Equality Inequality Contain Share
Spatial analysis Shortest path analysis: route location models for determining the minimum environmental cost determining allocations in a location allocation model trip assignment in transportation planning models automatic vehicle dispatch systems
Spatial analysis Vehicle routing: The development of routes or tours for deliveries and/or pickups from one or more depots (warehouses) at one or more stops (delivery or pick-up points) Such problems become more complex when there are time constraints at either the depots or the stops or both and when service times are variable (In some problems vehicle capacity is a serious constraint)
Spatial analysis Arc routing: In arc routing problems the GIS-T user is attempting to find routes which will allow for an optimal (or at least an efficient) transversal of a set of arcs in the transportation network Bus service and residential delivery Pick-up or monitoring systems (mail delivery, solid waste collection, or meter reading)
Spatial analysis Network flow models: The assignment problem which seeks an optimal matching, on a one-to-one basis, of demand and supply points within the network The so-called transportation problem which also seeks to satisfy a set of demand points from a set of supply points, but in which one supply point can service many demand points or alternatively one demand point can receive from many supply points The minimum-cost flow problem where not only link costs are considered but also link capacities and constraints (i.e. tunnel heights and bridge widths)
Spatial analysis Partitioning, clustering & regionalization: Need to create regions (i.e. sales territories or political districts) within a database In the former case it may then be necessary to solve network routing problems in order to provide the sales personnel with catchments or tours The objective is to design contiguous and compact regions with equal workloads Clustering procedures can be used to produce regions within point, line, or area layers and are especially useful in regionalising networks
Spatial analysis Location-allocation model: Location allocation models seek to determine optimal locations for private and public sector facilities (i.e. warehouses, factories, retail stores, ambulance depots, police stations, and fire stations) as well as optimal allocations of customers to these facilities (These models have been an important topic in geography and operations research)
References Bernhardsen T., 2002, Geographic Information Systems. An Introduction (3rd ed.), New York: John Wiley & Sons. Burrough P.A. & McDonnell R., 1998, Principles of Geographical Information Systems, Oxford: Oxford University Press. Claire R.W. & Guptill S.C., 1983, Spatial operators for selected data structures, In Proceedings of Auto-Carto 5 (Foreman J. ed.), Falls Church (Virginia): American Society of Photogrammetry & American Congress of Surveying & Mapping, pp. 201-12. McCormack E. & Nyerges T., 1997, What transportation modeling needs from a GIS: A conceptual framework, Transportation Planning & Technology, 21(1-2): 5-23. Waters N.M., 1999, Transportation GIS: GIS-T. In Geographical Information Systems. Management Issues & Applications, (Longley P.A., Goodchild M.F., Maguire D.J. & Rhind D.W. eds.), Vol. 2, (2nd ed.), New York: John Willey & Sons, pp. 827-44.
Χρηματοδότηση Το παρόν υλικό έχει αναπτυχθεί στα πλαίσια του εκπαιδευτικού έργου του διδάσκοντα. Το έργο υλοποιείται στο πλαίσιο του Επιχειρησιακού Προγράμματος «Εκπαίδευση και Δια Βίου Μάθηση» και συγχρηματοδοτείται από την Ευρωπαϊκή Ένωση (Ευρωπαϊκό Κοινωνικό Ταμείο) και από εθνικούς πόρους. 1