In recent years, ontology engineering has received a great amount of attention and has advanced g... more In recent years, ontology engineering has received a great amount of attention and has advanced greatly. Today, ontologies are finding their role in knowledge and information systems. To keep up with the dynamic aspect of knowledge, the need for ontology evolution systems has emerged. Such systems help facilitate the management of changes on the ontology in a systematic way. To define a systematic way of facilitating management of changes, a process model is needed. Therefore in this paper, we present our novel ontology evolution process model which uses ontology change rules to achieve this goal. These change rules are defined via the SWRL rule representation language. This new approach to ontology evolution helps the ontology evolution process by preserving the consistency of the ontology throughout the ontology evolution process. To classify ontology changes, we will also present our novel taxonomy of ontology changes. To test the feasibility of our presented process model, we ha...
The term "ontology" comes from the field of philosophy that is concerned with the study... more The term "ontology" comes from the field of philosophy that is concerned with the study of being or existence. In general computer science defines ontology as an "explicit specification of a conceptualization," which is, "the objects, concepts, and other entities that are presumed to exist in some area of interest and the relationships that hold among them". Ontologies hold a great importance to modern knowledge based systems. They enable shared knowledge and reuse where information resources can be communicated between human or software agentsand should be machine readable. Manual construction of ontologies is an expensive and time consuming task. An answer to this problem is to provide an automatic or semi- automatic tool for ontology construction. Over the past years, this field of research has not yet reached the goal of fully automating the ontology development process. In this paper we will review the ontology creation process with the help of ont...
An Ontology Merging Semantic Peer to Peer Framework
In this paper we provide a semantic peer to peer framework suitable for ontology merging in order... more In this paper we provide a semantic peer to peer framework suitable for ontology merging in order to create a larger and more global ontology. In our work we chose a hybrid approach for ontology merging which we think will perform best in large scale environments like the internet and can be used to convert the semantically heterogenic internet into a semantically homogeneous web. We chose our previous network SAN as a basis for our proposed framework. We chose it because of its �efficient routing capabilities and its �efficient broadcast mechanism. In our framework, after extending the capabilities of SAN, we are able to define a method for managing the merge of the ontologies in the community to create a shared global ontology for the community. By this, we can divide the workload of merging the ontologies between the nodes in each community. Also, we provide a method for clustering ontologies with respect to their main domain concepts. The global ontology of a community can be sh...
P2P networks were invented with the idea of sharing resources available on the Internet. Their ad... more P2P networks were invented with the idea of sharing resources available on the Internet. Their advantages include robustness in failures, extensive resource-sharing, self-organization, load balancing, data persistence, anonymity, etc. Today structured P2P networks are beginning to become more important because they make subsequent queries more efficient and in an internet like scale, query response time is very important. There are two main types of structured overlays: Distributed Hash Table based (DHT) and non-DHT based networks. HyperCup is an example of a non-DHT based structured overlay which is a symmetric overlay based on hypercubes. It has some problems in scalability from the network traffic point of view. DHT-based systems such as Content Addressable Network (CAN) have received a lot of attention and a lot of research has been done on them but still have a few problems, for example the lost indexing problem in CAN. Each of these two types also has its own advantages. In th...
Proceedings of the 39th Annual Hawaii International Conference on System Sciences (HICSS'06), 2006
Peer-to-peer networks are beginning to form the infrastructure of future applications. One of the... more Peer-to-peer networks are beginning to form the infrastructure of future applications. One of the problems with non structured peer-to-peer networks is their scalability limitation. These networks cant contain a large number of nodes because of the large amount of traffic that they have to handle. HyperCup is a structured overlay network that solves the scalability problem for message broadcasts. This
2006 Semantics, Knowledge and Grid, Second International Conference on, 2006
Peer-to-peer networks (P2P) are beginning to form the infrastructure of future applications. One ... more Peer-to-peer networks (P2P) are beginning to form the infrastructure of future applications. One of the problems with unstructured P2P networks is their scalability limitation. This is also the problem in structured P2P networks that use broadcasting to find objects. These networks can't contain a large number of nodes because of the large amount of traffic that they have to handle. Local indexing is a method to reduce this traffic. But local indexes tend to become large with the growth of the network. Also limiting the size of these indexes causes loss of indexing information. In this paper we introduce a novel ontology based local index which limits the size of the local indexes without losing indexing information. We show that the method can be employed by many P2P networks. We also, as an example, apply this local index on HyperCup overlay network, and show that it reduces the network traffic significantly.
The term "ontology" comes from the field of philosophy that is concerned with the study... more The term "ontology" comes from the field of philosophy that is concerned with the study of being or existence. In general computer science defines ontology as an "explicit specification of a conceptualization," which is, "the objects, concepts, and other entities that are presumed to exist in some area of interest and the relationships that hold among them”. Ontologies hold a great importance to modern knowledge based systems. They enable shared knowledge and reuse where information resources can be communicated between human or software agentsand should be machine readable. Manual construction of ontologies is an expensive and time consuming task. An answer to this problem is to provide an automatic or semi- automatic tool for ontology construction. Over the past years, this field of research has not yet reached the goal of fully automating the ontology development process. In this paper we will review the ontology creation process with the help of ontology...
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Papers by Ali Rahnama