Applied Mechanics and Materials Vol. 696

Abstract: Some diseases, particularly cardiovascular disease, will change the shape and structure of retinal vessels. Observation and detection of retinal vessels play an important role in the diagnosis of diseases. Traditional diagnosis of the retinal vessels that ophthalmologist perform under artificial visual attending. Image segmentation based on Markov random field is a method based on statistical theory, which takes into account the correlation between the local pixels, uses the prior knowledge effectively, has fewer model parameters and is easy to be combined with other methods etc., so this method has been widely researched and applied in the field of image segmentation. This paper which mainly studied the Markov random field is how to specific apply to image segmentation, and the iterated conditional mode and the traditional segmentation (clustering) algorithm segmented and compared in the medical retinal vessel image. The method of MRF can effectively restrain the noise in the vessel segmentation.

Abstract: Because of its excellent electrical properties, the insulation sheath is widely used in outdoor power equipment terminal stop position. The performance of the insulation sheath will directly affect the normal operation of electrical equipment. For the insulation sheath detection rely mainly on traditional electrical insulation testing means. This article through using ANSYS finite element simulation software to simulate the hole type defects of the insulation sheath. Then combination of X-ray DR detection system with traditional electrical insulation testing method, testing of three insulation sheath, the test results are consistent with the simulation results. At the same time, this article illustrates the possibility and the reliability of X-ray DR detection system on the insulation sheath.

Abstract: Background: The rapid and efficient identification of bacterial aerosol become important in clinical application, public health, and manufacturing increasingly. Laser-induced-fluorescence is an important method for identifying bacteria from environmental aerosol. This method is real-time, can operate 24-hour without pretreatment, and even remotely. Objective: Choosing the optimal excitation and emission wavelength and designing an appropriate analysis apparatus fulfill identification of bacterial aerosol. Method: First, fluorescence spectral data of five different strains of bacteria (S.aureus, E.coli, Bacillus subtilis, salmonella, Vibrio Parahaemolyticus) and three types of disruptors (pollen, leave powder, cloth fiber) were obtained by Three-dimensional fluorescent spectrometer. Second, the original spectral data was preprocessed and analyzed in light of common laser wavelength. Last, the optimal excitation and emission wavelength was chosen based on the balance of identification performance and fabricating cost. Result: Experiments showed that choosing ex:266nm/em:354nm and ex:337nm/em:394nm as ex/em wavelength can meet the requirement to identify bacterial aerosol specifically. Furthermore, the 337nm/394nm wavelength had more practical value. Conclusion: Choosing 337nm wavelength laser as excitation light inducing intrinsic the fluorophores within bacterial aerosol and receiving emission fluorescence with 394nm bandpass light filter can differentiate bacteria from disruptors in environmental aerosol efficiently.

Abstract: Based on side lateral scattering technique, a particle analysis apparatus for clinical liquid sample provided a precise and accurate method to acknowledge and transversely compare the particle properties at the micro-level. To improve the detection capability and lessen the lower detection limit of particle size, a photoelectric detection circuit including two parts of pre-amplifier and noise reduction was designed in accordance with the properties of lateral scattering signals. The circuit has the characteristics of working stable at high frequency band, high SNR and wide dynamic input range. Experiments show that the apparatus with the circuit mentioned can detect 0.3μm particle effectively and has broad application prospects in differential blood count, injection quality control and many other areas.

Abstract: Acoustics vibration detection is detected the displacement of post insulator by inspection the change of vibration state. Hoe to indentify the situation of insulator accurately from vibration signal is fate for acoustics vibration detection. According to analyzing the vibration date with statistics method, it is proved that the vibration frequency distribution of the same type of insulator follow normal distribution. Based on this conclusion, the identification frequency section has been set for identifying breached insulators.

Abstract: Allocation of spectrum resource is the key for heterogeneous wireless networks. Taking the differences between different types of access networks available channel bandwidth and the communication requirements of users into consideration on the basis of cognitive heterogeneous network spectrum resource allocation algorithm based on graph coloring theory, this paper introduces bandwidth control parameter and proposes a spectrum resource allocation algorithm based on user needs feedback, which improves the utilization and fairness of system spectrum resources.

Abstract: In this paper, combining the existing dynamic access control model based on trust with the dynamic measurement technique, we propose a dynamic access control scheme based on credibility. By the simulation test, the mechanism can prevent the malicious behavior of malicious nodes.

Abstract: In the cloud computing mode TCCP, there exist shortcomings of overburdened trusted TC, the anonymity of nodes and configuration information of platform can’t be guaranteed. In this paper, we propose an anonymous scheme based on attribute certificate. The scheme is achieved by the trusted ring signature based on attribute certificate. By the security analysis, the anonymity and platform configuration information of computing nodes is guaranteed. By simulation experiment, we obtain the efficiency of the scheme. Comparing with Boneh ring signature based on ECC algorithm, this scheme has a great superiority in terms of large amount of ring signatures.

Abstract: Remote attestation is the key technology of trusted computing. The existing remote attestation techniques lack of the trust measure of platform running state. In this paper, by the analysis and comparison of existing remote attestation technology, we propose a trust measure of platform running state, and a remote attestation program based on the trust measure results. By RO security analysis, and a simulation, we verify the security and efficiency of the program. The trust measure of platform running state is mainly based on the trust rating of the programs running on the platform, and a total trust value of the platform by an algorithm. The remote attestation for the trust measure of platform running state is based on K-CCA problem. In this paper, we carry out simulation experiment with different proportions of non-credible nodes and the experiment results verify the trust evaluation efficiency of the scheme on the platform.

Abstract: Cloud computing is a new technology for complex systems shared among numerous users. Therefore, for the trust and security of the cloud computing, authentication of users is a significant issue. Based on the fact that SSL Authentication Protocol (SAP) applied in cloud computing undergo a heavy computation and communication, we support the protocol based on the identity-based hierarchical model for cloud computing in this paper. By random oracle, we give the proof of the security of the protocol.