Biblio

This paper presents an IoT enabled real time occupancy semantic search system leveraging ETSI defined context information and interface meta model standard- ``Next Generation Service Interface for Linked Data'' (NGSI-LD). It facilitates interoperability, integration and federation of information exchange related to spatial infrastructure among geo-distributed deployed IoT entities, different stakeholders, and process domains. This system, in the presented use case, solves the problem of adhoc booking of meetings in real time through semantic discovery of spatial data and metadata related to room occupancy and thus enables optimum utilization of spatial infrastructure in university campuses. Therefore, the proposed system has the capability to save on effort, cost and productivity in institutional spatial management contexts in the longer run and as well provide a new enriched user experience in smart public buildings. Additionally, the system empowers different stakeholders to plan, forecast and fulfill their spatial infrastructure requirements through semantic data search analysis and real time data driven planning. The initial performance results of the system have shown quick response enabled semantic discovery of data and metadata (textless2 seconds mostly). The proposed system would be a steppingstone towards smart management of spatial infrastructure which offers scalability, federation, vendor agnostic ecosystem, seamless interoperability and integration and security by design. The proposed system provides the fundamental work for its extension and potential in relevant spatial domains of the future.

Semantic data has semantic information about the relationship between information and resources of data collected in a smart city so that all different domains and data can be organically connected. Various services using semantic data such as public data integration of smart cities, semantic search, and linked open data are emerging, and services that open and freely use semantic data are also increasing. By using semantic data, it is possible to create a variety of services regardless of platform and resource characteristics. However, despite the many advantages of semantic data, it is not easy to use because it requires a high understanding of semantics such as SPARQL. Therefore, in this paper, we propose a semantic framework for users of semantic data so that new services can be created without a high understanding of semantics. The semantics framework includes a template-based annotator that supports automatically generating semantic data based on user input and a semantic REST API that allows you to utilize semantic data without understanding SPAROL.

Cloud service providers offer a low-cost and convenient solution to host unstructured data. However, cloud services act as third-party solutions and do not provide control of the data to users. This has raised security and privacy concerns for many organizations (users) with sensitive data to utilize cloud-based solutions. User-side encryption can potentially address these concerns by establishing user-centric cloud services and granting data control to the user. Nonetheless, user-side encryption limits the ability to process (e.g., search) encrypted data on the cloud. Accordingly, in this research, we provide a framework that enables processing (in particular, searching) of encrypted multiorganizational (i.e., multi-source) big data without revealing the data to cloud provider. Our framework leverages locality feature of edge computing to offer a user-centric search ability in a realtime manner. In particular, the edge system intelligently predicts the user's search pattern and prunes the multi-source big data search space to reduce the search time. The pruning system is based on efficient sampling from the clustered big dataset on the cloud. For each cluster, the pruning system dynamically samples appropriate number of terms based on the user's search tendency, so that the cluster is optimally represented. We developed a prototype of a user-centric search system and evaluated it against multiple datasets. Experimental results demonstrate 27% improvement in the pruning quality and search accuracy.

In this article, I present the questions that I seek to answer in my PhD research. I posit to analyze natural language text with the help of semantic annotations and mine important events for navigating large text corpora. Semantic annotations such as named entities, geographic locations, and temporal expressions can help us mine events from the given corpora. These events thus provide us with useful means to discover the locked knowledge in them. I pose three problems that can help unlock this knowledge vault in semantically annotated text corpora: i. identifying important events; ii. semantic search; iii. and event analytics.

Searchable encryption is a new developing information security technique and it enables users to search over encrypted data through keywords without having to decrypt it at first. In the last decade, many researchers are engaging in the field of searchable encryption and have proposed a series of efficient search schemes over encrypted cloud data. It is the time to survey this field to conclude a comprehensive framework by analyzing individual contributions. This paper focuses on the searchable encryption schemes in cloud. We firstly summarize the general model and threat model in searchable encryption schemes, and then present the privacy-preserving issues in these schemes. In addition, we compare the efficiency and security between semantic search and preferred search in detail. At last, some open issues and research challenges in the future are proposed.