Biblio

The engine is a significant and dynamic component of the aircraft. Because of the complicated structure and severe operating environment, the fault detection of the engine has always been the key and difficult issue in the field of reliability. Based on an engine and the acoustic emission technology, we propose a method of identifying fault types and determining different components in the engine by constructing the attenuation coefficient. There are several common faults of engines, and three different types of fault sources are generated experimentally in this work. Then the fault signal of the above fault sources propagating in different engine components are obtained. Finally, the acoustic emission characteristics of the fault signal are extracted and judged by the attenuation coefficient. The work effectively identifies different types of faults and studies the effects of different structural components on the propagation of fault acoustic emission signals, which provides a method for the use of acoustic emission technology to identify the faults types of the engine and to study the propagation characteristics of AE signals on the engine.*

With the development of cloud computing and its economic benefit, more and more companies and individuals outsource their data and computation to clouds. Meanwhile, the business way of resource outsourcing makes the data out of control from its owner and results in many security issues. The existing secure keyword search methods assume that cloud servers are curious-but-honest or partial honest, which makes them powerless to deal with the deliberately falsified or fabricated results of insider attacks. In this paper, we propose a verifiable single keyword top-k search scheme against insider attacks which can verify the integrity of search results. Data owners generate verification codes (VCs) for the corresponding files, which embed the ordered sequence information of the relevance scores between files and keywords. Then files and corresponding VCs are outsourced to cloud servers. When a data user performs a keyword search in cloud servers, the qualified result files are determined according to the relevance scores between the files and the interested keyword and then returned to the data user together with a VC. The integrity of the result files is verified by data users through reconstructing a new VC on the received files and comparing it with the received one. Performance evaluation have been conducted to demonstrate the efficiency and result redundancy of the proposed scheme.

Elliptic Curve Cryptography (ECC) is a promising public key cryptography, probably takes the place of RSA. Not only ECC uses less memory, key pair generation and signing are considerably faster, but also ECC's key size is less than that of RSA while it achieves the same level of security. However, the magic behind RSA and its friends can be easily explained, is also widely understood, the foundations of ECC are still a mystery to most of us. This paper's aims are to provide detailed mathematical foundations of ECC, especially, the subgroup and its generator (also called base point) formed by one elliptic curve are researched as highlights, because they are very important for practical ECC implementation. The related algorithms and their implementation details are demonstrated, which is useful for the computing devices with restricted resource, such as embedded systems, mobile devices and IoT devices.

In this paper a joint algorithm was designed to detect a variety of unauthorized access risks in multilevel hybrid cloud. First of all, the access history is recorded among different virtual machines in multilevel hybrid cloud using the global flow diagram. Then, the global flow graph is taken as auxiliary decision-making basis to design legitimacy detection algorithm based data access and is represented by formal representation, Finally the implement process was specified, and the algorithm can effectively detect operating against regulations such as simple unauthorized level across, beyond indirect unauthorized and other irregularities.