Qualitative Linguistic Terms and Geographic Concepts: Quantifiers in Definitions

Definitions of categories in existent geospatial ontologies are an invaluable source of information because they provide us with essential knowledge about concepts and their properties. A closer examination reveals that definitions also contain supplementary linguistic items, which are mainly qualitative expressions, such as quantifiers. This inclusion of modifiers in definitions affects the way values are assigned to the categories’ properties (semantic properties and relations). This paper introduces a methodology for: (1) representing the essence of qualitative information to clarify the identity relations among categories; and (2) assessing their semantic similarity in order to disambiguate the taxonomic structure of existent geospatial ontologies.     

Upper Holocene sea-level changes: Paleogeographic evolution and its impact on coastal archaeological sites and monuments

The paper presents the evolution of the geographic environment imposed by sea-level changes in selected sites of the Aegean Sea region during the Upper Holocene. The changes are due, mainly, to paroxysmic phases of the actual neotectonic evolution and to differential—in time and space—block movements, and emerged or submerged coasts. The reconstitution of these coasts is presented and, in some cases, natural harbor morphology is revealed. The use and evolution of these sites is discussed. Other sites concern coastal or inland ancient settlements or constructions affected by submersion by the sea, by the rise of the groundwater table, or by uplift movements. A general discussion on engineering measures to be applied for protection of the antiquities affected by these geographic changes closes the presentation.     

Zur Gliederung Ostgriechenlands in tektonische Zonen

Zusammenfassung Aus den neueren geologischen Beobachtungen und Kartierungen in Griechenland folgt, daß die tektonische Aufgliederung Griechenlands nachRenz, zumindest in Ostgriechenland, nicht zu Recht besteht. An Stelle einer tektonischen Trennung haben wir kontinuierliche sedimentäre Übergänge. Gewiß gibt es tektonische Kontakte an kleineren und größeren Überschiebungen und einem verbreiteten Schuppenbau, aber diese Störungen beweisen keine tektonische Längsgliederung in Fazieszonen, für welcheRenz ein so reiches stratigraphisches Material erarbeitet hat.     

Geo-scape,a granularity depended spatialization tool for visualizing multidimensional data sets

Recently,the expertise accumulated in the field of geovisualization has found application in the visualization of abstract multidimensional data,on the basis of methods called spatialization methods.Spatialization methods aim at visualizing multidimensional data into low-dimensional representational spaces by making use of spatial metaphors and applying dimension reduction techniques.Spatial metaphors are able to provide a metaphoric framework for the visualization of information at different levels of gran...     

Brittle-Ductile Transition and Hoek–Brown mi Constant of Low-Porosity Carbonate Rocks

Geotechnical and Geological Engineering - The mechanical behavior of low porosity carbonate rocks is investigated by a series of conventional triaxial compression tests performed at room...     

Ground zoning against seismic hazard in Athens, Greece

The 1999, Ms=5.9, Athens earthquake caused serious structural damage to buildings in the western part of Athens, Greece. This paper presents the ground zoning against seismic hazard proposed shortly after the earthquake in order to aid reconstruction of the area. Existing engineering geological and geotechnical data were combined with local observations to provide a unified set of classification criteria, consistent with provisions of the Greek Seismic Code EAK. The accuracy and the possible limitations of this zoning procedure are addressed through comparison with observed damage distribution as well as results from seismic ground response analyses performed at sites with well established soil profiles. There is clear evidence that the proposed zones correspond to geological formations exhibiting grossly different seismic response with regard to the design of common engineering structures. However, the mostly qualitative nature of the guidelines for ground categorisation provided by EAK and the general lack of systematic, site-specific geotechnical data for the whole area induce uncertainties in the definition of the seismic design actions for the different zones. These objective uncertainties certainly demand increased conservatism but do not limit application of the proposed methodology for first aid, preliminary planning in the event of destructive earthquakes.     

A Framework for Intensional and Extensional Integration of Geographic Ontologies

This paper presents ongoing research in the field of extensional mappings between ontologies. Hitherto, the task of generating mappings between ontologies has focused on the intensional level of ontologies. The term intensional level herein, refers to the set of concepts that are included in an ontology. However, an ontology that has been created for a specific task or application needs to be populated with instances. These comprise the extensional level of an ontology. This particular level is generally neglected during the ontologies’ integration procedure. Thus, although methodologies of geographic ontologies integration, ranging from alignment to true integration, have, in the course of years, presented a solid ground for information exchange, little has been done in exploring the relationships between the data. In this context, this research strives to set a framework for extensional mappings between ontologies using Information Flow Theory by presenting a case study of interoperability between the thematic content of maps.     

Permeability in flysch �� Distribution decrease with depth and grout curtains under dams

A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation, their comparison and their decrease with depth is discussed. The depth where a permeability of 3 to 5×10-7m/sec can be retained (the limit of a reasonable grouting under a high dam) may be twofold if the geological history of the formation could not contain a compressional tectonic process. This depth may reach 100m in some cases. The differences in the mean values of permeability among the various litho-types are minor, while the presence of siltstones, always present although with varied participation, dramatically controls the global permeability.     

Umbrella Arch Nomenclature and Selection Methodology for Temporary Support Systems for the Design and Construction of Tunnels

This paper argues that there is a requirement for standardized nomenclature and a selection methodology for a particular class of temporary support. The authors have chosen the term Umbrella Arch (UA) to define the method of support that acts as pre-support that is installed during the first pass of the excavation around and above the crown of the tunnel face. The UA supports the rock mass and the tunnel face predominately by transferring loading longitudinally through the interaction of the support and surrounding ground condition. There are three categories of UA. Categorization depends on the type of support element used. These elements include: (1) Spiles; (2) Forepoles; and (3) Grouted. These categories can be further divided into 11 sub-categories quantified by the amount of grout utilized in the installation. The sub-categories are justified by the employment of each sub-category within a support selection methodology for an UA; this was created by the authors based on experience and through a comprehensive literature search that included published papers as well as design reports. The collection of publications has resulted in 141 permutations of different temporary tunnel support in varying weak and difficult geological condition. The UA support selection methodology was created to aid tunnel designers in these conditions with the basic concepts for the appropriate selection process for an UA. Furthermore, the authors quantified the support selection methodology through the employment of other pre-existing design charts and empirical evidence to create a new design tool, the UA selection chart. Overall, this paper hopes to achieve the creation of an international standard with respect to UA and UA support element nomenclature and a better understanding for the selection of a particular UA sub-category.     

Geo-scape,a granularity depended spatialization tool for visualizing multidimensional data sets

Recently, the expertise accumulated in the field of geovisualization has found application in the visualization of abstract multidimensional data, on the basis of methods called spatialization methods. Spatialization methods aim at visualizing multidimensional data into low-dimensional representational spaces by making use of spatial metaphors and applying dimension reduction techniques. Spatial metaphors are able to provide a metaphoric framework for the visualization of information at different levels of granularity. The present paper makes an investigation on how the issue of granularity is handled in the context of representative examples of spatialization methods. Furthermore, this paper introduces the prototyping tool Geo-Scape, which provides an interactive spatialization environment for representing and exploring multidimensional data at different levels of granularity, by making use of a kernel density estimation technique and on the landscape “smoothness” metaphor. A demonstration scenario is presented next to show how Geo-Scape helps to discover knowledge into a large set of data, by grouping them into meaningful clusters on the basis of a similarity measure and organizing them at different levels of granularity.