Applications based on CC (cloud computing) has the potential efficient and low-cost advantages, while there are the lack of computing power, the limited range of applications and the higher cost of BIM (Building Information Model) applications in the traditional desktop mode. According to BIM application features and the actual situation, the paper starts from the concept of CC and discusses the advantages of BIM applications using CC. The system framework, the key technologies and the implementation methods of the BIM application platform based on CC have been put forward on the basis of the above discussion.

In microelectromechanical systems, F-P cavity is one of the most common structures, air cavity thickness of a F-P cavity is about a near wavelength, the thickness of the air cavity is less and the interference series is low, so the reflective phases of the reflectors have much influence on the peak wavelength. The linear relationship between the thickness of an air cavity in a tunable filter and the resonant wavelength is deduced and tested by numerical computation in the article. The research is of practical significance for the design of a F-P cavity tunable wavelength selector.

Because the SIFT (scale invariant feature transform) algorithm can not accurately locate the flame shape features and computationally intensive, this article proposed a stereo video image fire flame matching method which is a combination of Harris corner and SIFT algorithm. Firstly, the algorithm extracts image feature points using Harris operator in Gaussian scale space and defines the main directions for each feature point, and then calculates the 32-dimensional feature vectors of each feature point descriptor and the Euclidean distance to match two images. Experimental results of image matching demonstrate that the new algorithm improves the significance of the shape of the extracted feature points and keep a better match rate of 96%. At the same time the time complexity is reduced by 27.8%. This algorithm has a certain practicality.

“Virtual architecture” is a combination product of architecture and information science, the paper introduces the features of virtual architecture system from its application implementation, and discusses in depth the key technologies from building life cycle, such as BIM technology, notology, digital photogrammetry, virtual reality and parametric design, which hope for borrowing ideas on its implementation from the paper.

The reliability of Radio Frequency Identification (RFID) mechanism is disturbed by illegal tracking and information intercepted.The paper proposed a new active RFID authentication protocol based on the dynamic tag ID and encryption key,which transforms the tag ID using chaotic transformation during authentication and communication between the reader and tags,and realizes mutual authentication of the reader and tags.Through the analysis of security, the protocol not only can ensure the integrity, fresh and confidentiality of data, but also can effectively prevent illegal tracking labels and replay attack.