Advanced Materials Research Vol. 646

Abstract: The cloud environment is recently emphasized when we save a large amount of data with a minimum of maintenance. But the cloud is a variable environment that data is likely to be changed when which is transferred, and even doesn't permanently store. Besides it has the risk of phishing from a third party. A scalable storage space as one of the features of the cloud has to consist as more proactive access control, secure encryption, and key management in the aspect of the size of the database and the number of users. In this paper, we analyze about database security requirements of these environment and the provided encryption technologies of until now. And, even anyone who don't have the expertise for security assessment and management or CC could be easily accessible it.

Abstract: The arc-fault is the main reason that cause electric fires. The technology of arc-fault circuit interrupters (AFCI) is the new circuit protection technology and it could avoid arc-fault causing fire effectively. The appearance of arc-fault can not be predicted. The traditional time domain or frequency domain analysis method for arc-fault signal processing is not ideal because it’s inaccurate and not in time. This paper bases on characteristics of arc-fault signals and analyzes the series connection arc-fault signal by Daubechies wavelet transform in 4 orders. As a result, it can provide the characteristics of arc-fault and detect arc-fault effectively and timely. This method is confirmed reliability by the simulation result and provides the theoretical basis of the development of AFCI.

Abstract: Dependences of distribution, penetration, reflection and absorption of microwaves in the layers of conductive micro-particles on the frequency of the incident radiation and size of particles are obtained and investigated. Layers of conductive spherical particles as the shell, and without it are accepted in our work as the most common model of powder metals. So, this study allows to describe and classify features of electromagnetic wave heating of various metal powders and to predict the performance, in which it will be effective heating of metal powders by electromagnetic radiation.

Abstract: Based on the theory of H-bridge multilevel converter, the structure of a three phase cascaded multilevel inverter (LVCMI) and its control strategy are proposed in this paper. Several standard three-phase bridges can be reconnected into a new single three-phase bridge at ac-side. Simulation results show that such topological structure can increase the output voltage capacity and reduce the THD. It can be used as an inverter or rectifier in three phase system. In theory, it can be cascaded unlimitedly. The more cascaded, the higher output voltage and the lower THD. Experimental results of LVCMI with 3-module verified the feasibility of the proposed inverter.