Information Model. Core Elements In this Section, we provide some preliminary ideas for the definition of an information model as part of the PoF Reference Model, following the approach used in OAIS. The information model again focuses on the needs of bridging the gap between the Active System and the DPS. In order to meet the requirements of a variety of systems on the site of the Active System as well as on the site of the DPS, the information model has been kept quite generic in this reference model. The core elements of the information model are represented by the UML diagram de- picted in Figure 10, where we included the main types used to represent the objects of preservation. The core element of the information model is an Archival Object (see Figure 10), which is made up of a Content Object and a Context Object. Content Object and Context Object are linked to each other by a gives context link. Both Content Object and Context Object are of type Archival Resource, which is described by a Metadata type and is represented by an Information Object type. An Information Object can be a Single Object such as a photo, a file, or a concept or it can be a Complex Object. An important type of Complex Object is a Collec- tion of objects that are to be archived together. A second type of Complex Object is an Object Graph of interlinked Information Object types. Context is represented by either a Local Context or a World Context type. The Local Context has to be stored in the PDS, because it can, in future, not be easily found elsewhere. World Context is context information that is expected that also in future can be found somewhere else and, thus, it might be sufficient to store only some Figure 10: Abstract Information Model of the PoF Reference Model references to keep this context information. See deliverable D6.1 [ForgetIT, 2013c] for a more detailed discussion of this issue. The information model drafted here will be further refined and described with all details in the next version of the PoF Reference Model, in deliverable D8.5 [ForgetIT, 2016].
Information Model. In this section, we describe the information model as part of the PoF (Preserve or Forget) Reference Model which bridges the gap between the Active System and the DPS. In order to meet the requirements of a variety of systems on the site of the Active System as well as on the site of the DPS, the information model has been designed to be flexible, extensible and inter-operable. The target of the PoF Information Model is twofold: a) it should reflect the perspective of the User, i.e., the active system, thus enabling the active system to interact with the PoF compliant system and b) it should reflect the perspective of the Middleware in order to support all the needed information for storing content in the archive and for retieving it from the archive. Therefore, we present two perspectives of the information model, the user perspective (see Figure 12) and the Middleware perspective (see Figure 13). The information model presented in this deliverable has been developed based on the very preliminary information model presented in deliverable D8.2 [Xxxxx et al., 2015b]. The three core elements of the ForgetIT Information Model are: • Content • Context • Situation Content, obviously, represents the content to be preserved. Context provides additional information helping in the interpretation of the content, as required when considering the long-term perspective. Situation provides a high level structuring concept for archival content. The meaning of Situation is discussed in more detail in the next section, before the information model as a whole is presented.
Information Model. The information model defines the structure (e.g. relations, attributes) of all the information (data) that is handled in a system on a conceptual level. This includes the modelling of the main concepts for information flow, storage and how they are related. The description of the representation of the information (e.g. binary, XML, RDF etc.) and concrete implementations are not part of the information model but can be found in the information view (see Section 3.3) and the related design choices (see Section 5.3.1.2). 0..* 0..*
Information Model. The diagram in Figure 13 shows the structure of the information that is handled and processed in an IoT System. The main aspects are represented by the elements VirtualEntity, ServiceDescription and Association. A VirtualEntity models a PhysicalEntity, a ServiceDescription describes a service that acts as a bridge to the physical world, and finally an Association models the connection between the two. Every VirtualEntity has a unique identifier or entityType, defining the type of the entity representation, e.g. a human, a car or even a temperature sensor. Furthermore, a VirtualEntity can have zero to n different attributes (Attribute). The entityType may refer to concepts in an ontology that may define what attributes a VirtualEntity of this type may have (see, for instance, [33]). Each attribute has a name (attributeName), a type (attributeType), and one to n values (ValueContainer). This way, one can for instance, model an attribute nearbyDevices, which itself has several values. Each ValueContainer groups one Value and zero to n metadata information units (MetaData) belonging to the given Value. The metadata can, for instance, be used to save the timestamp of the value, or other quality parameters, such as accuracy. The VirtualEntity is also connected to the ServiceDescription via the ServiceEntityAssociation. A ServiceDescription describes the relevant aspects of a Service, including its interface. In addition it may contain one (or more) ResourceDescription describing a Resource whose functionality is exposed by the Service. The ResourceDescription in turn may contain information about the Device on which the Resource is hosted.
Information Model. The basic building block of the model described is the resource, which is defined as an entity with: A globally unique id A type An unordered list of properties Properties are defined as: A key (i.e. the property’s id) A value and associated type o A property can be either of a simple type, or a reference to another resource Special types of components are containers which can include other components. An example of a resource with two properties, one of which is a reference to another resource, is given in Figure 2.
Information Model. The information model for the DCN monitoring service is mostly derived from the model of the statistics defined in the OpenFlow specification [OF], with group, table, port, queue, meter, individual and aggregate flow statistics. However, it has been extended to include specific statistics for the optical ports, as shown in Figure 8. Figure 8 – Information model for the DCN information service
Information Model. Figure 10 shows an UML representation for the information model that captures policy-related resources in the data store. A Policy object comprises a Match object which identifies the target resource, and an Action object which defines the specific action to be enforced on that resource. There can be various types of policies (PolicyImpl), which implement the Policy interface. Because policies may have different scopes, they are grouped in containers (PolicyContainer). A specific implementation (PolicyContainerImpl) of the PolicyContainer interface defines a logical group of policies that relate to each other, possibly requiring conflict resolution among them.
Information Model. The information model comprises three constituent parts: documentation, non-graphical information and graphical information. NOTE The model is conveyed using PDF, COBie and native model files.
Information Model. An information model in software engineering is a representation of concepts and the relationships, constraints, rules, and operations to specify data semantics for a chosen domain of discourse. Internet Map Server (IMS) – server software which allows users to share, view and edit geospatial data via Open Geospatial Consortium (OGC) standards such as WMS, WFS and WCS. K Key Mark-up Language (KML) – an XML based language schema for expressing geographic features and visualisation on maps. KML was developed for use with Google Earth, in 2008 KML became an international standard of the Open Geospatial Consortium. L
Information Model
