The main aim of this work is to describe in detail how to develop an instrument, with the goal of collecting and managing a great deal of both geological and geophysical data acquired using different survey typologies...The main aim of this work is to describe in detail how to develop an instrument, with the goal of collecting and managing a great deal of both geological and geophysical data acquired using different survey typologies in Eastern Sicily (Italy). The opportunity to manage different categories of data, at the same time, allows us to have a complete view of the complex area studied. This paper discusses a software package that has been designed to enhance the efficiency of applying a range of geological and geophysical data. More than 12000 records are archived: boreholes represent 81% of the data and 19% is geophysical data. In this paper it is illustrated how both kinds of data, thanks to the functionalities of the database and the possibility of connecting to a Geographical Information System (GIS), can be used in a variety of different geological studies. We present four studies where is relevant the use of the database, in detail, we show a morpho-structural study, an examination of the spectral analysis of the noise data, an update of the geological and geotechnical maps, and a classification of the areas on the basis of the distribution of the shear wave velocity in the firsts 30 meters (Vs30). They are just some examples of the potentialities of a relational database.展开更多
Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infr...Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infrastructure for ocean and marine data management) made it necessary to use XML (Extensible Markup Language) as a standard file format for sharing data and metadata. At present, the Italian National Oceanographic Data Centre (OGS/NODC) has all its data and metadata contained in an Oracle relational database, and the metadata is managed using XML formats and schema (XSD;XML Schema Definition), giving common vocabularies for parameters, instruments, ships, etc. in agreement with European project standards. One problem with XML is the dynamic change in metadata schemas (XSD), necessitating development of a system which is flexible and capable of managing the changes. This paper describes a system for managing oceanographic metadata using XML files and the functionalities provided by the Oracle database. To better manage the XML format, we chose to load into the OGS/NODC database the whole XML file, using a dedicated field. The database Oracle gives us the flexibility to manage the XML format locally, within the OGS/NODC information system, using the XML DB (XML DataBase) Oracle features. This, through the use of XMLType, allows the inclusion of the XML into the database. Furthermore, through the use of the XQuery functions it is possible to create a set of views through which information contained in the XML can be viewed more immediately in a relational form. Using the XML and the XQuery functions, it is possible to store, extract and manage different kinds of information that might be exchanged at the European level. Moreover, with a RESTful (Representational State Transfer) Web Service, we have a simple and standard interface for rapidly and easily creating, modifying and deleting records containing XML files inside the database. Finally, through the use of a RESTful Web Service, it is possible to decouple the application from the database, so that through the use of software that manages HTTP URLs, such as the Mikado (SeaDataNet project), the XML file can be inserted, updated and deleted inside the database without the need for a direct connection to it.展开更多
Spectral element methods are well established in the field of wave propagation,in particular because they inherit the flexibility of finite element methods and have low numerical dispersion error.The latter is experim...Spectral element methods are well established in the field of wave propagation,in particular because they inherit the flexibility of finite element methods and have low numerical dispersion error.The latter is experimentally acknowledged,but has been theoretically shown only in limited cases,such as Cartesian meshes.It is well known that a finite element mesh can contain distorted elements that generate numerical errors for very large distortions.In the present work,we study the effect of element distortion on the numerical dispersion error and determine the distortion range in which an accurate solution is obtained for a given error tolerance.We also discuss a double-grid calculation of the spectral element matrices that preserves accuracy in deformed geometries.展开更多
文摘The main aim of this work is to describe in detail how to develop an instrument, with the goal of collecting and managing a great deal of both geological and geophysical data acquired using different survey typologies in Eastern Sicily (Italy). The opportunity to manage different categories of data, at the same time, allows us to have a complete view of the complex area studied. This paper discusses a software package that has been designed to enhance the efficiency of applying a range of geological and geophysical data. More than 12000 records are archived: boreholes represent 81% of the data and 19% is geophysical data. In this paper it is illustrated how both kinds of data, thanks to the functionalities of the database and the possibility of connecting to a Geographical Information System (GIS), can be used in a variety of different geological studies. We present four studies where is relevant the use of the database, in detail, we show a morpho-structural study, an examination of the spectral analysis of the noise data, an update of the geological and geotechnical maps, and a classification of the areas on the basis of the distribution of the shear wave velocity in the firsts 30 meters (Vs30). They are just some examples of the potentialities of a relational database.
文摘Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infrastructure for ocean and marine data management) made it necessary to use XML (Extensible Markup Language) as a standard file format for sharing data and metadata. At present, the Italian National Oceanographic Data Centre (OGS/NODC) has all its data and metadata contained in an Oracle relational database, and the metadata is managed using XML formats and schema (XSD;XML Schema Definition), giving common vocabularies for parameters, instruments, ships, etc. in agreement with European project standards. One problem with XML is the dynamic change in metadata schemas (XSD), necessitating development of a system which is flexible and capable of managing the changes. This paper describes a system for managing oceanographic metadata using XML files and the functionalities provided by the Oracle database. To better manage the XML format, we chose to load into the OGS/NODC database the whole XML file, using a dedicated field. The database Oracle gives us the flexibility to manage the XML format locally, within the OGS/NODC information system, using the XML DB (XML DataBase) Oracle features. This, through the use of XMLType, allows the inclusion of the XML into the database. Furthermore, through the use of the XQuery functions it is possible to create a set of views through which information contained in the XML can be viewed more immediately in a relational form. Using the XML and the XQuery functions, it is possible to store, extract and manage different kinds of information that might be exchanged at the European level. Moreover, with a RESTful (Representational State Transfer) Web Service, we have a simple and standard interface for rapidly and easily creating, modifying and deleting records containing XML files inside the database. Finally, through the use of a RESTful Web Service, it is possible to decouple the application from the database, so that through the use of software that manages HTTP URLs, such as the Mikado (SeaDataNet project), the XML file can be inserted, updated and deleted inside the database without the need for a direct connection to it.
基金funded in part by the SPICE-Marie Curie RTN project(contract MRTN-CT-2003-504267)supported by the ICTP Programme for Training and Research in Italian Laboratories,Trieste,Italy,and by CNPq,Brazil,under grant 314553/2009-6.
文摘Spectral element methods are well established in the field of wave propagation,in particular because they inherit the flexibility of finite element methods and have low numerical dispersion error.The latter is experimentally acknowledged,but has been theoretically shown only in limited cases,such as Cartesian meshes.It is well known that a finite element mesh can contain distorted elements that generate numerical errors for very large distortions.In the present work,we study the effect of element distortion on the numerical dispersion error and determine the distortion range in which an accurate solution is obtained for a given error tolerance.We also discuss a double-grid calculation of the spectral element matrices that preserves accuracy in deformed geometries.
