Applied Mechanics and Materials Vols. 568-570

Abstract: A novel and sensitive method has been successfully developed for quantitative detection of invA gene of Salmonella. The surface of sensor chip was modified and then target sequence and probe-2 were induced, which formed a sandwich structure. Under optimal conditions, the SPR-based DNA sensor displayed a linear range of 200 pM - 10 nM and a low detection limit of 200 pM for synthetic target sequence. The excellent sensitivity and high stability of the designed biosensor, make this strategy a promising tool for Salmonella screening.

Abstract: In this paper, we discuss the data losses problem in state estimation process. In sensor network, due to the energy constrained and communication constrained, the system suffering varying data dropped problem, which include independent package dropped, related dropped in single data package transmission processing and partial package dropout in multiple data package transmission processing. Based on the proposed state estimation over sensor network model, the corresponding mathematical models are built and analyzed.

Abstract: Aim at intelligence requirements, a reconnaissance monitoring system in battlefield is designed. The basic unit of this system is sensor node which has functions of condition information monitoring and wireless communication. The node has a long reconnaissance and monitor to anthropogenic shock, acoustic, coordinate, temperature and humidity of surface, and so on, and access to analyze climate condition and enemy deployment, which provides commanders intelligences of battlefield.

Abstract: A method of measuring inclination based on MEMS accelerometer is introduced,and a digital inclination sensor is developed. This paper describes the hardware structure of sensor and working principle. MEMS-based accelerometer senses axial component of gravity in sensitivity-axis direction. MSP430 microcontroller does temperature self-compensation in the light of the temperature drift fitting curve while the thermometer monitors environment temperature. IIR filtering algorithm is adopt to eliminate disturbance from high-frequency vibration noises. In order to analyze characteristics in frequency domain, Butterworth filter is simulated and filtering coefficients are given by MATLAB. The sensor is calibrated to eliminate angle drifts by RS232 interface. The result shows that the measuring accuracy of inclination sensor is up to 0.002°.

Abstract: On the basis of thermal measuring method, a hot-film gas flow sensor is proposed. Its sensitive element is a FS5 probe, which is integrated with measuring resistance and temperature compensating resistance inside. In order to achieve temperature compensation, the main measuring circuit is designed. Considering minimizing errors in this circuit, the temperature correcting circuit is added to further modify output voltage. By fitting measurement data of gas flow and the final output voltage with least square method, an operating characteristic curve is obtained as well as its 4th order polynomial. Under equivalent conditions, the proposed sensor, a high-precision standard sensor and an industrial sensor are experimented upon and the contrast analysis of their measurement results is given. The experimental results prove that the proposed sensor has high precision with measurement error less than 3%. Therefore the proposed sensor is feasible for industrial applications.

Abstract: Graphene oxide (GO)/nafion (Nf) film was immobilized onto the pretreated glassy carbon electrode (GCE) surface. Electrochemically reduced graphene oxide (ERGO)/Nf/AuNPs nanocomposite was synthesized by electrochemical reduction and deposition, which was characterized by cyclic voltammetry (CV) and square wave voltammetry (SWV). The experimental results revealed that the ERGO/Nf/AuNPs nanocomposite was stable, excellent, and homogeneous electrochemical property.

Abstract: The communication security problems for wireless sensor networks are exacerbated by the limited power and energy of the sensor devices. The focus of this paper is to design a lightweight group key management scheme to safeguard the data packet passing on the sensor networks. The design of the protocol is motivated by the observation that many sensor nodes in the network play different roles. We describe the design and implementation of establishing different pairwise keys based on LEACH. The protocol contains group communication policies, group membership requirements for secure communication under different types of attacks.

Abstract: Although the Gaussian mixture probability hypothesis density (GMPHD) filter is a multi-target tracker that can alleviate the computational intractability of the optimal multi-target Bayes filter and its computational complex is lower than that of sequential Monte Carlo probability hypothesis density (SMCPHD), its computational burden can be reduced further. In the standard GMPHD filter, each observation should be matched with each component when the PHD is updated. In practice, time cost of evaluating many unlikely measurements-to-components parings is wasteful, because their contribution is very limited. As a result, a substantial reduction in complexity could be obtained by directly setting relative value associated with these parings. A fast GMPHD algorithm is proposed in the paper based on gating strategy. Simulation results show that the fast GMPHD can save computational time by 60%~70% without any degradation in performance compared with standard GMPHD.

Abstract: the unstable approach caused by the distortion of glideslope, endangers aircraft in the forms of over-pitching, stalling at low altitude, and exceeding the limitation of descent rate. Aiming at the issues above, this paper presents a glideslope distortion correction model based on the fusion of multi-navigation sensors. Model simulations have been done to prove the effectiveness of the model, and the results show that the correction model can enhance the stability of glideslope effectively.

Abstract: In this paper, we propose and analyze an new MAC protocol based on node pair sequencing (MAP-NPS), which requires node pairs achieved successful handshakes to realize multiple transmissions orderly after one-off RTS-CTS competition. We analyze and assess the protocol’s performance via simulations. Compared to the MACA-U [1] protocol and the PCAP [2] protocol, we show that the new protocol have better performance,which can improve throughput, decrease the propagation delay and reduce hidden terminals and exposed terminals.