Internet of Things (IoT) is a novel and emerging paradigm to connect real/physical and virtual/logical world together. So, it will be necessary to apply other related scientific concepts in order to achieve this goal. The main focus of this paper is to identify the research topics in IoT. For this purpose, a comprehensive study has been conducted on the vast range of research articles. IoT concepts and issues are classified into some research domains and sub-domains based on the analysis of reviewed papers that have been published in 2015 & 2016. Then, these domains and sub-domains have been discussed as well as it is reported their statistical results. The obtained results of analysis show the most of the IoT research works are concentrated on technology and software services domains similarly at first rank, communication at second rank and trust management at third rank with 19%, 14% and 13% respectively. Also, a more accurate analysis indicates the most important and challenging sub-domains of mentioned domains which are: WSN, cloud computing, smart applications, M2M communication and security. Accordingly, this study will offer a useful and applicable broad viewpoint for researchers. In fact, our study indicates the current trends of IoT area. Manuscript profile

Vehicular communications have been considered to be an enabler for numerous vehicle safety and information applications.Vehicle Social Networks (VSNs) are a type of ad-hoc networks which allows wireless communication between two adjacent vehicles. Routing and communicating with adjacent nodes are one of the problems in VSNs. A literature review indicated that the time limit to transmit data and route is a problem due to the geographical distance and speed.. Manuscript profile

Currently, industry and academia have shown much interest in security and privacy protection on the blockchain used in various applications. Attacks like privacy leakage and data loss make conventional methods vulnerable before emerging blockchain technology. Blockchain is a decentralized and tamper-resistant public ledger technology that guarantees security and data reliability in a peer-to-peer network. Many fields have employed blockchain, from the beginning cryptocurrency to the smart contract, social services, industry, and artificial intelligence. There are blockchain reports on vulnerabilities and security, but they lack a comprehensive survey in attacks, privacy, and security views. In this survey, we first briefly overviewed blockchain. Second, we discussed challenges and issues on the blockchain. Third, we focused on the blockchain attacks, including their cause and targeted area. We also displayed possible preventive measures in the blockchain attack. Finally, we conducted a systematic study on solutions to the blockchain security increase. In addition, this survey included blockchain privacy techniques. Manuscript profile

The user cold start challenge, occurs when a user joins the system which used recommender systems, for the first time. Since the recommender system has no knowledge of the user preferences at first, it will be difficult to make appropriate recommendations. In this paper, users’ demographics information are used for clustering to find the users with similar preferences in order to improve the cold start challenge by employing the kmeans, k-medoids, and k-prototypes algorithms. The target user’s neighbors are determined by using a hybrid similarity measure including a combination of users’ demographics information similarity and users rating similarity. The asymmetric Pearson correlation coefficient utilized to calculate the user rating similarity, whereas GMR (i.e., global most rated) and GUC(i.e., global user local clustering) strategies are adopted to make recommendations. The proposed method was implemented on MovieLens dataset. The results of this research shows that the MAE of the proposed method has improved the accuracy of the proposals up to about 26% compared to the GMR method and up to about 34% compared to the GUC method. Also, the results show about 60% improvement in terms of rating coverage compared to the GMR and GUC methods. Manuscript profile