Applied Mechanics and Materials Vols. 738-739

Abstract: In this paper a low-cost Micro-Electro-Mechanical System (MEMS) inertial measurement unit is designed, a 3-axis accelerometer and 3-axis gyroscope simulated 6 degrees of freedom orientation sensing through sensor fusion. By analyzing a simple complimentary filter and a more complex Kalman filter, the outputs of each sensor were combined and took advantage of the benefits of both sensors to improved results. The experimental results demonstrate that the output signal can be corrected suitability by means of the proposed method.

Abstract: With concern for chemicals leak in transportation, there is an urgent need for a sensor which can quickly and accurately detect chemicals. In this study, a high-sensitivity gas sensor was demonstrated, which is based on high-field asymmetric waveform ion mobility spectrometry technology with corona discharge (CD) used as the ionization source to product gas-phase ion samples, which can get the response in one second. The effects of dispersion voltage and moisture were investigated.

Abstract: Since the Security Infrastructure Construction Standard for Civil Aviation Transportation Airport (MH/T 7003-2008) revised by Civil Aviation Administration of China in 2008, more and more technologies have been applied in the airport security to meet the standard requirements. With the advent of internet of things era, the things interconnection and the coordination sensation of sensor network technology provide a new technical means for airport security. A perimeter intrusion detection system (PIDS) based on sensor network is proposed and designed for safeguarding airport flight area from illegal intrusion. The PIDS consists of a front-end detection sub-system, a control center sub-system, a network transmission sub-system, a power supply sub-system, an intelligent video sub-system , a video monitor sub-system, a combination meteorological sub-system and a lighting and sound alarm sub-system.It can accurately identify the type of intrusion, locate the intrusion target, and reduce false alarms caused by environmental interference. The PIDS based on sensor network has been successfully applied in the security of Shanghai Pudong International Airport flight area.

Abstract: An enzyme amplified immunosensor for highly sensitive detection of Ractopamine (RAC) in foodstuff was developed based on quartz crystal microbalance (QCM). The high sensitivity was achieved by enzyme-AuNPs signal amplification strategy and magnetic β-cyclodextrins (β-CD) enrichment capacity. The novel QCM immunosensor which combines with the advantages of high selectivity of immunoassays and the high sensitivity of QCM has been developed for the determination of trace residues of RAC in food production. Under optimum conditions, the differences in the frequencies (∆f) of the QCM were proportional to the concentration of RAC over the range from 0.01 to 10 ng mL^-1. The minimal detection limit was 0.01 ng mL^-1. Due to its high sensitivity, acceptable stability and good selectivity, the immunosensor realized reliable quantification of RAC in real foodstuff. The proposed project has the potential to become a successful on-site screening method in food safety.

Abstract: Recently, photonic crystal fibers (PCFs) have attracted many researchers because of their special characteristics, and design flexibility that cannot be realized by conventional fibers. One of the important areas of research is the optical fiber hydrophones. In this paper, the finite element solver COMSOL multiphysics (FES) is used to study and compare the phase sensitivity to acoustic pressure of a hollow-core photonic band gap fiber (HC-PBF), and a conventional single-mode fiber (SMF) for various acoustic pressures in the frequency range from 10 kHz to 50 kHz. Simulation results of the investigated optical fibers show that the normalized responsivity (NR) to acoustic pressure of the investigated HC-PBF, and SMF are-344 dB, and-366 dB, respectively.

Abstract: Several studies have demonstrated that significant energy consumption reduction of nodes and network energy hole elimination can be achieved by introducing a mobile sink. In most related researches, mobile sink's energy is always assumed to be sufficient to collect data sensed by normal nodes. However, mobile sink consumes large amounts of energy in practical applications and it is impossible to own infinite energy. Correspondingly, the moving path plan of the mobile sink, which can be treated as a TSP (Travelling Salesman Problem), plays an important role in reducing and balancing network energy consumption. In this paper, an energy efficient mobile sink path planning strategy (EEPP) is proposed. In this strategy, LEACH protocol is introduced to balance the static network energy consumption; A heuristic path optimization method is utilized to further shorten the mobile sink path and reduce network latency. Simulation results show that our algorithm has good performance on the network energy consumption balancing, thus extending the network lifetime.

Abstract: An improvement strategy is proposed for the traditional DV-hop scheme in WSNs, with the purpose of enhancing its robustness to the range error and getting higher localization accuracy. The strategy is using a combination of Min-max and Steepest Descend method as the node position derivation algorithm to replace Lateration which is used in the original scheme. Simulation shows that the improved scheme outperforms the original scheme in terms of the localization accuracy as the network connection topology varies.

Abstract: This paper presents an Embedded Smart Home system solution using wireless sensor network (WSN). The Smart Home system can be sectioned into four parts: wireless sensor network, embedded smart control centre, Server and Client. The major technical of the wireless sensor network is ZigBee. The wireless sensor network includes coordinator node and Sensor node. It is developed based on the Z-Stack protocol stack and the wireless chip CC2530. It is mainly responsible for collecting the environmental parameter of the house and controlling the electrical equipment in the house. It can also support the RFID access control and camera monitor. The control centre communicates with the wireless sensor network by the serial port. It communicates with Server by the TCP socket and transmits data to each client, or communicates with the client by using the wireless communication module directly. Partial hardware electric diagram and software flowchart were provided. Field using indicates that this system is economical and flexible.

Abstract: Middleware for wireless sensor networks (WSNs) can help bridge the gap and remove impediments. Publish/Subscribe (P/S) is an asynchronous communication paradigm that supports many-to-many interactions between a set of clients. P/S paradigm is a suitable paradigm for WSNs middleware. This paper designs PSWSN, a WSNs middleware, whose architecture is composed of service management, P/S support and access management. Service management is an information publishing platform based on B/S mode, its main function is to abstract the various business functions into services. P/S support in PSWSN is a core and supports publishing and matching services. Access management is employed so that WSNs can be abstracted and accessed as logical rather than individual physical entities.

Abstract: In order to support characters of data acquisition system of smart grid, such as scalable and plug and play, one configurable node of sensor network was proposed. The number of protocol standard, the number of interface of each protocol standard, the number of senor of each interface and the number of byte of each sensor can be configured in this node. All these parameters can be configured according to the specific application of smart grid and then achieve the best balance between cost and performance. One real model was implemented by VHDL and the number of protocol standard, the number of interface of each protocol standard, the number of sensor of each interface, the number of byte of each sensor can be configured in the range from 1 to 8. The correctness and validity of this real model were confirmed by simulation results of configurable level and one application instance.