الفهرس 
Introduction 2 Chapter 1Only 14 pages are availabe for public view
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Abstract
In an era where data is considered the new oil, the lack of meaning and well-defined data structure will lead to interoperability and usability problems. Ontologies are a representation paradigm to capture and represent the knowledge of a universe of discourse and structure it in a machine-comprehensible format. However, developing ontologies can be a time-consuming, expensive process and requires a significant investment, which is challenging to make by a single person or organization. An effective approach to tackling this problem is building ontologies collaboratively where all interested stakeholders are involved. It includes identifying the main terms and concepts by finding a consensus among stakeholders while defining a shared terminology and formalizing it for the intended domain.
The process of jointly building ontologies in distributed environments, which we refer to as collaborative ontology development, aims to accomplish shared objectives and extensive coordination of activities. Ontologies are instrumental in this process by providing formal specifications of shared semantics. In this ”complex” and dynamic setting, a collaborative change process model requires more powerful engineering, argumentation, and negotiation methodologies.
In fact, the main challenge for stakeholders is to work collaboratively on a shared objective constructively and efficiently while avoiding misunderstandings, uncertainty, and ambiguity. The involved stakeholders, which may be geographically distributed, should easily express and integrate their diverse views and ideas without risking losing the original intention. Researchers have presented methodologies and platforms to allow ontology construction in various scenarios. However, there is still little understanding of and support for the evolutionary aspects of ontologies. This is particularly crucial in distributed and collaborative settings such as the Semantic Web, where ontologies naturally co-evolve with their communities of use.
Software Engineering offers many techniques and tools for teams’ collaboration, teams’ management, feedback management, versioning, merging, and evolving software artifacts. Many of these techniques can be reused in an ontology engineering setting. Scrum/Nexus/Spotify are Frameworks that enable iterative and incremental product development. This thesis leverages these frameworks and maps them to the collaborative, inter-organizational domain ontology building and evolution. Besides, we adopted software measurement criteria as a candidate evaluation framework for ontology quality assessment.
Another challenge exists as to how humans can see, imagine and understand the knowledge captured in different domains. The knowledge experts and teams need to analyze the quality of ontologies generated in collaborative environments quickly. They must have tools that provide them with a set of metrics and charts that let them know which parts of the ontology have problems, how to enhance some other parts, the complexity and memory consumption if we wish to traverse this ontology with the inference engine and so on. To overcome this severe problem, we adopted a set of software insights and architectural analysis techniques that significantly impact ontology building, evolution, evaluation, and review process. We visualized all the calculations of the ontology evaluation metrics described in the previous point using many interactive tools to instantly assimilate and understand a broad set of ontologies properties, problems and proposed enhancements.
Still, however, the Semantic Web is an incomplete dream to build domain ontologies on a broad scale of worldwide teams, agents, research centers and organizations. However, a homogeneous revolutionary platform as a network of Blockchains could be the solution to this. Our thesis proposed a new model to build or evolve the ontologies via worldwide consensus through the blockchain network. However, using a blockchain alone is not enough. The exact Blockchain chosen, the consensus mechanisms used, and the architecture of the voting (consensus) platform are all critical design decisions that impact system capabilities. Our thesis described architectural concerns for robust, upgradable, multi-user smart contracts used by WOL to fulfill the collaboration socio-technical requirements and all the required features to accomplish a true collaborative ontology evolution process.
Yet, there are several criteria to validate or evaluate an ontology. To do that, and as a pioneering thinking model in this research, we let each node apply its automatic or semi-automatic way of validation on the transaction. If we think about this, if each research center, company, or even an individual one, has a validation mechanism, all of these nodes will be challenged on a global scope to prove the robustness and efficiency of their automatic validation and evaluation mechanisms. We called this phenomenon “Survival of the Fittest.” According to the Blockchain consensus algorithm(s), that transaction must be validated by 51% of the nodes or validated by quorums at the next nomination to be considered a valid transaction. Once a node gets a consensus on the transaction, the algorithm will reward this node with some reputation wealth credit. This will steer the research effort to enhance automatic or semi-automatic ontology validation and evaluation mechanisms. In addition, since we are rewarding the nodes or quorums by credit, the most powerful and fittest validation and evaluation techniques will survive for a longer time and will be got famous after a while.