The traditional tourism services tend to use tourism resources as the center. They ignore individual characteristics and contextual information of the user side. The provided service is static, and doesnt meet the real needs of the users. A service mechanism based on context awareness is presented which consists of data, platform and services. It sets up data center based on users and gets context data according to rules .It uses the cloud computing technology to provide distributed processing, storage and retrieval capability for big data. It also establishes tourism service confirming to requirements of the users and dynamic adjusts service mode according to the user context information. Simulation results show that the mechanism can realize the demand for tourism services in conjunction with the individual characteristics of user.

Distributed Denial of Service (DDoS) attacks is always one of the major problems for service providers. Using blockchain to detect DDoS attacks is one of the current popular methods. However, the problems of high time overhead and cost exist in the most of the blockchain methods for detecting DDoS attacks. This paper proposes a blockchain-based collaborative detection method for DDoS attacks. First, the trained DDoS attack detection model is encrypted by the Intel Software Guard Extensions (SGX), which provides high security for uploading the DDoS attack detection model to the blockchain. Secondly, the service provider uploads the encrypted model to Inter Planetary File System (IPFS) and then a corresponding Content-ID (CID) is generated by IPFS which greatly saves the cost of uploading encrypted models to the blockchain. In addition, due to the small amount of model data, the time cost of uploading the DDoS attack detection model is greatly reduced. Finally, through the blockchain and smart contracts, the CID is distributed to other service providers, who can use the CID to download the corresponding DDoS attack detection model from IPFS. Blockchain provides a decentralized, trusted and tamper-proof environment for service providers. Besides, smart contracts and IPFS greatly improve the distribution efficiency of the model, while the distribution of CID greatly improves the efficiency of the transmission on the blockchain. In this way, the purpose of collaborative detection can be achieved, and the time cost of transmission on blockchain and IPFS can be considerably saved. We designed a blockchain-based DDoS attack collaborative detection framework to improve the data transmission efficiency on the blockchain, and use IPFS to greatly reduce the cost of the distribution model. In the experiment, compared with most blockchain-based method for DDoS attack detection, the proposed model using blockchain distribution shows the advantages of low cost and latency. The remote authentication mechanism of Intel SGX provides high security and integrity, and ensures the availability of distributed models.

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Management of grid resource information is a challenging and important area considering the potential size of the grid and wide range of resources in grid system. These huge amounts of resources often have different structures and functions. How to manage resources effective is an urgent problem for grid technology. WSDM is about defining a common manageability structure and message exchange format, defines a Web service message protocol for management information, and a management interface for a manageable resource present on the Web. Taking a real case of storage grid system, a practice application of grid resource management based on Web Services Distributed Management (WSDM) is given in this paper. This paper also discusses the disadvantages of WSDM application in the area.