AS NZS ISO 19101.1:2015 pdf free download – Geographic information – Reference model
the communication channel (e.g. the Internet) using its own concepts and vocabulary. Once the message reaches its destination, the provider agent interprets the request. This means that the provider agent identifies concepts it knows that correspond to the request and for which it has information, and uses them to answer the request (e.g. Eiffel Tower, Champ de Mars, Paris, 48*51’29” Latitude, 2°1740” Longitude]. Then, the provider agent assembles the information in a response that is sent back to the user agent. In turn, at the time when the user agent receives the response from the provider agent, it interprets and assesses it according to its initial request. Interoperability happens in this scenario between the two agents only if the answer of the provider agent satisfies the user agent query. Figure 1 illustrates the interaction between a user agent and a provider agent in the conceptual framework for the interoperability of geographic information. First, it considers the reality (R) as it is at a given time and about which the user agent is interested to have information. Second, the user agent model of the reality (R’] results from a set of observed signals and the frame of reference that is used to build it, i.e. the set of rules and knowledge used to abstract phenomena. The user agent model is made of properties considered meaningful that are organized or structured into concepts. A concept is an abstract, generalized, and simplified representation of similar real world phenomena. A concept is entirely fictional, i.e. it does not exist in reality. Because concepts are purely abstractions, the user agent cannot communicate concepts directly to the provider agent. Therefore, the user agent’s concepts shall be transformed into physical representations, which then can be transmitted through the communication channel. In communication, this refers to the encoding operation.
When the message reaches its destination, the provider agent begins the decoding operation, which consists of the recognition of and the assignment of an appropriate meaning to the message’s physical representations. Although under perfect conditions representations of concepts induce user agent’s isomorphic concepts to the provider agent, typically, representations of concepts induce concepts to the provider agent (R”) that are of similar meaning to user agent’s concepts. These concepts are then used to answer the user agent’s query. Based on these concepts, the provider agent begins the retrieval of information. Similarly to R’, the retrieved information (either concepts or instances of them) cannot be communicated directly since it consists of features. Consequently, it shall be encoded into physical representations, arranged in a message (R”) to be placed as a reply (e.g. an XML encoding of Eiffel Tower, Champ de Mars, Paris, 48951’29”Latitude, 2°17’40”Longitude) on the communication channel towards the user agent. Once again here when placed on the communication channel, the physical representations are freed of their provider agent’s meaning. In turn, at the time the response message is received, the user agent initiates the decoding operation to recognize the components of the message and to give them a meaning and, after, assesses if that meaning infers the concepts in R’. If it is the case, the user and the provider agents interoperate successfully. This conceptual framework describes interoperability of geographic information from an interpersonal communication perspective between two agents. Interoperability of geographic information consists of a bi-directional process that includes feedback in both directions to ensure that messages get to their destination and are understood properly. Each agent uses its own knowledge and vocabulary to express and interpret features. As long as the two agents have a common background and a common set of symbols, they regularly end up understanding each other.