Journal of Sensors http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. A Novel Nonlinear Multitarget -Degree Coverage Preservation Protocol in Wireless Sensor Networks Thu, 25 Aug 2016 16:57:27 +0000 http://www.hindawi.com/journals/js/2016/3434961/ Due to the existence of a large number of redundant data in the process of covering multiple targets, the effective coverage of monitored region decreases, causing the network to consume more energy. To solve this problem, this paper proposes a multitarget -degree coverage preservation protocol. Firstly, the affiliation between the sensor nodes and target nodes is established in the network model; meanwhile the method used to calculate the coverage expectation value of the monitored region is put forward; secondly, in the aspect of the network energy conversion, use scheduling mechanisms on the sensor nodes to balance the network energy and achieve different network coverage quality with energy conversion between different nodes. Finally, simulation results show that NMCP can improve the network lifetime by effectively reducing the number of active nodes to meet certain coverage requirements. Zeyu Sun, Xiaofei Xing, Chuanfeng Li, Yalin Nie, and Yangjie Cao Copyright © 2016 Zeyu Sun et al. All rights reserved. Applying a Locally Linear Embedding Algorithm for Feature Extraction and Visualization of MI-EEG Thu, 25 Aug 2016 16:02:54 +0000 http://www.hindawi.com/journals/js/2016/7481946/ Robotic-assisted rehabilitation system based on Brain-Computer Interface (BCI) is an applicable solution for stroke survivors with a poorly functioning hemiparetic arm. The key technique for rehabilitation system is the feature extraction of Motor Imagery Electroencephalography (MI-EEG), which is a nonlinear time-varying and nonstationary signal with remarkable time-frequency characteristic. Though a few people have made efforts to explore the nonlinear nature from the perspective of manifold learning, they hardly take into full account both time-frequency feature and nonlinear nature. In this paper, a novel feature extraction method is proposed based on the Locally Linear Embedding (LLE) algorithm and DWT. The multiscale multiresolution analysis is implemented for MI-EEG by DWT. LLE is applied to the approximation components to extract the nonlinear features, and the statistics of the detail components are calculated to obtain the time-frequency features. Then, the two features are combined serially. A backpropagation neural network is optimized by genetic algorithm and employed as a classifier to evaluate the effectiveness of the proposed method. The experiment results of 10-fold cross validation on a public BCI Competition dataset show that the nonlinear features visually display obvious clustering distribution and the fused features improve the classification accuracy and stability. This paper successfully achieves application of manifold learning in BCI. Mingai Li, Xinyong Luo, Jinfu Yang, and Yanjun Sun Copyright © 2016 Mingai Li et al. All rights reserved. Voltammetric Determination of Epinephrine in Pharmaceutical Sample with a Tyrosinase Nanobiosensor Thu, 25 Aug 2016 13:30:16 +0000 http://www.hindawi.com/journals/js/2016/5653975/ A novel carbon paste electrode modified with a multiwalled carbon nanotube (MWCNT), tyrosinase, and Nafion membrane (CP/MWCNT/Tyr/Nafion) was developed for voltammetric determination of epinephrine (EP). The CP/MWCNT/Tyr/Nafion biosensor exhibited linear dynamic range from  M to  M EP concentration with a good correlation coefficient (). The detection limit of the biosensor was calculated as  M EP from the signal-to-noise ratio (S/N = 3). Reproducibility of the biosensor was also calculated from relative standard deviation as 3.8% (). Ascorbic acid (AA) and uric acid (UA) did not interfere in the quantification of epinephrine. The developed biosensor was also successfully applied for the determination of epinephrine in pharmaceutical sample. The CP/MWCNT/Tyr/Nafion biosensor has good sensitivity, selectivity, stability, easy preparation procedure, and short analysis time and can be used for the determination of EP in pharmacological samples. Şenol Alpat, Kazım Özdemir, and Sibel Kılınç Alpat Copyright © 2016 Şenol Alpat et al. All rights reserved. Monte Carlo Registration and Its Application with Autonomous Robots Thu, 25 Aug 2016 09:35:56 +0000 http://www.hindawi.com/journals/js/2016/2546819/ This work focuses on Monte Carlo registration methods and their application with autonomous robots. A streaming and an offline variant are developed, both based on a particle filter. The streaming registration is performed in real-time during data acquisition with a laser striper allowing for on-the-fly pose estimation. Thus, the acquired data can be instantly utilized, for example, for object modeling or robot manipulation, and the laser scan can be aborted after convergence. Curvature features are calculated online and the estimated poses are optimized in the particle weighting step. For sampling the pose particles, uniform, normal, and Bingham distributions are compared. The methods are evaluated with a high-precision laser striper attached to an industrial robot and with a noisy Time-of-Flight camera attached to service robots. The shown applications range from robot assisted teleoperation, over autonomous object modeling, to mobile robot localization. Christian Rink, Simon Kriegel, Daniel Seth, Maximilian Denninger, Zoltan-Csaba Marton, and Tim Bodenmüller Copyright © 2016 Christian Rink et al. All rights reserved. Internal Deformation Monitoring of Slope Based on BOTDR Wed, 24 Aug 2016 13:24:26 +0000 http://www.hindawi.com/journals/js/2016/9496285/ To overcome the shortcomings of conventional slope monitoring methods, this paper presented an in-place inclinometer based on BOTDR (Brillouin Optical Time Domain Reflectometer) which was used to obtain the long-term internal deformation in the slope. The installation process of optical fiber sensors and its measuring principle were introduced. The result of analysis indicated that the error in the measured displacement was proportional to the square of the inclinometer length and the precision of the BOTDR instrument, while it was inversely proportional to the diameter of the inclinometer tube. An actual field slope deformation monitoring case was also introduced. The results show that the BOTDR based inclinometer has a good consistency with the traditional inclinometer. It can effectively access the internal deformation of the slope and help to find the position of potential sliding surface accurately. This technology shows a high reliability and practicality in engineering application that will promote deeper research of slope in the future. Yijie Sun, Bin Shi, Dan Zhang, Hengjin Tong, Guangqing Wei, and Hongzhong Xu Copyright © 2016 Yijie Sun et al. All rights reserved. Simulation and Analysis of Uncooled Microbolometer for Serial Readout Architecture Tue, 23 Aug 2016 12:25:03 +0000 http://www.hindawi.com/journals/js/2016/9751056/ A detailed thermal behavior and theoretical analysis of uncooled resistive microbolometer is presented along with the proposed thermal imager simulator. An accurate model of a thermal detector is required to design a readout circuit that can compensate for the noise due to process variability and self-heating. This paper presents a realistic simulation model of microbolometer that addresses the fixed pattern noise, Johnson noise, and self-heating. Different simulations were performed to study the impact of infrared power and bias power on the performance of microbolometers. The microbolometers were biased with different bias currents along with different thermal parameters of the reference microbolometer to analyze the impact of self-heating on the thermal image. The proposed thermal imager simulator is used as a tool to visually analyze the impact of noise on the quality of a thermal image. This simulator not only helps in compensating the noise prior to the implementation in Analog Design Environment, but also can be used as a platform to explore different readout architectures. In this work, serial readout architecture was simulated with a row of blind microbolometers that served as a reference. Moreover, the algorithm for the proposed thermal imager simulator is presented. Musaed Alhussein and Syed Irtaza Haider Copyright © 2016 Musaed Alhussein and Syed Irtaza Haider. All rights reserved. Energy Efficiency of Ultra-Low-Power Bicycle Wireless Sensor Networks Based on a Combination of Power Reduction Techniques Tue, 23 Aug 2016 08:17:14 +0000 http://www.hindawi.com/journals/js/2016/7314207/ In most wireless sensor network (WSN) applications, the sensor nodes (SNs) are battery powered and the amount of energy consumed by the nodes in the network determines the network lifespan. For future Internet of Things (IoT) applications, reducing energy consumption of SNs has become mandatory. In this paper, an ultra-low-power nRF24L01 wireless protocol is considered for a bicycle WSN. The power consumption of the mobile node on the cycle track was modified by combining adjustable data rate, sleep/wake, and transmission power control (TPC) based on two algorithms. The first algorithm was a TPC-based distance estimation, which adopted a novel hybrid particle swarm optimization-artificial neural network (PSO-ANN) using the received signal strength indicator (RSSI), while the second algorithm was a novel TPC-based accelerometer using inclination angle of the bicycle on the cycle track. Based on the second algorithm, the power consumption of the mobile and master nodes can be improved compared with the first algorithm and constant transmitted power level. In addition, an analytical model is derived to correlate the power consumption and data rate of the mobile node. The results indicate that the power savings based on the two algorithms outperformed the conventional operation (i.e., without power reduction algorithm) by 78%. Sadik Kamel Gharghan, Rosdiadee Nordin, and Mahamod Ismail Copyright © 2016 Sadik Kamel Gharghan et al. All rights reserved. On-Chip Correlator for Passive Wireless SAW Multisensor Systems Thu, 18 Aug 2016 16:30:04 +0000 http://www.hindawi.com/journals/js/2016/2583063/ For decoding the asynchronous superposition of response signals from different sensors, it is a challenge to achieve correlation in a code division multiplexing (CDM) based passive wireless surface acoustic wave (SAW) multisensor system. Therefore, an on-chip correlator scheme is developed in this paper. In contrast to conventional CDM-based systems, this novel scheme enables the correlations to be operated at the SAW sensors, instead of the reader. Thus, the response signals arriving at the reader are the result of cross-correlation on the chips. It is then easy for the reader to distinguish the sensor that is matched with the interrogating signal. The operation principle, signal analysis, and simulation of the novel scheme are described in the paper. The simulation results show the response signals from the correlations of the sensors. A clear spike pulse is presented in the response signals, when a sensor code is matched with the interrogating code. Simulations verify the feasibility of the on-chip correlator concept. Liqiang Xie, Tianxian Wang, Ping Wang, and Jianchun Xing Copyright © 2016 Liqiang Xie et al. All rights reserved. Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings Thu, 18 Aug 2016 11:17:11 +0000 http://www.hindawi.com/journals/js/2016/8129387/ Novel protein sensors based on tapered optical fibres modified with Au coatings deposited using two different procedures are proposed. Au-based coatings are deposited onto a nonadiabatic tapered optical fibre using (i) a novel facile method composed of layer-by-layer deposition consisting of polycation (poly(allylamine hydrochloride), PAH) and negatively charged SiO2 nanoparticles (NPs) followed by the deposition of the charged Au NPs and (ii) the sputtering technique. The Au NPs and Au thin film surfaces are then modified with biotin in order to bind streptavidin (SV) molecules and detect them. The sensing principle is based on the sensitivity of the transmission spectrum of the device to changes in the refractive index of the coatings induced by the SV binding to the biotin. Both sensors showed high sensitivity to SV, with the lowest measured concentration levels below 2.5 nM. The calculated binding constant for the biotin-SV pair was  M−1 when a tapered fibre modified with the LbL method was used, with a limit of detection (LoD) of 271 pM. The sensor formed using sputtering had a binding constant of  M−1 with a LoD of 806 pM. These new structures and their simple fabrication technique could be used to develop other biosensors. Aitor Urrutia, Kartheka Bojan, Leonel Marques, Kevin Mullaney, Javier Goicoechea, Stephen James, Matt Clark, Ralph Tatam, and Sergiy Korposh Copyright © 2016 Aitor Urrutia et al. All rights reserved. EGFET pH Sensor Performance Dependence on Sputtered TiO2 Sensing Membrane Deposition Temperature Thu, 18 Aug 2016 07:01:30 +0000 http://www.hindawi.com/journals/js/2016/7594531/ Titanium dioxide (TiO2) thin films were sputtered by radio frequency (RF) magnetron sputtering method and have been employed as the sensing membrane of an extended gate field effect transistor (EGFET) for pH sensing detection application. The TiO2 thin films were deposited onto indium tin oxide (ITO) coated glass substrates at room temperature and 200°C, respectively. The effect of deposition temperature on thin film properties and pH detection application was analyzed. The TiO2 samples used as the sensing membrane for EGFET pH-sensor and the current-voltage (I-V), hysteresis, and drift characteristics were examined. The sensitivity of TiO2 EGFET sensing membrane was obtained from the transfer characteristic (I-V) curves for different substrate heating temperatures. TiO2 thin film sputtered at room temperature achieved higher sensitivity of 59.89 mV/pH compared to the one deposited at 200°C indicating lower sensitivity of 37.60 mV/pH. Moreover the hysteresis and the drift of TiO2 thin film deposited at room temperature showed lower values compared to the one at 200°C. We have also tested the effect of operating temperature on the performance of the EGFET pH-sensing and found that the temperature effect was very minimal. Khairul Aimi Yusof, Rohanieza Abdul Rahman, Muhammad AlHadi Zulkefle, Sukreen Hana Herman, and Wan Fazlida Hanim Abdullah Copyright © 2016 Khairul Aimi Yusof et al. All rights reserved. Embedded Systems for Mobile Sensors Wed, 17 Aug 2016 12:03:21 +0000 http://www.hindawi.com/journals/js/2016/8312032/ Marco Anisetti, Valerio Bellandi, Abdellah Chehri, Yurong Qian, and Gwanggil Jeon Copyright © 2016 Marco Anisetti et al. All rights reserved. Measurement of Circumferential Liquid Film Based on LIF and Virtual Stereo Vision Sensor Wed, 17 Aug 2016 09:46:38 +0000 http://www.hindawi.com/journals/js/2016/2872947/ Gas-liquid annular flow is widely used in many industrial applications such as petroleum, chemical, and nuclear engineering. The feature parameters of liquid film in the annular flow are of great significance to understand the flow characteristics and measure the flow precisely. For the annular flow, the circumferential features of liquid film are more important than the axial features to acquire abundant flow structures and reveal the flow mechanism. In the paper, a measurement platform based on the laser-induced fluorescence (LIF) and virtual stereo vision sensor is presented. The virtual stereo vision sensor comprises a high-speed camera and two optical reflection sets, which can acquire the liquid film from two views simultaneously and reconstruct the features of liquid film. Image processing techniques are proceeded with to extract the feature parameters of liquid film; then the circumferential flow characteristic can be reconstructed by views transformation and fusion. The flow characteristic based on the thickness distribution is analysed. The experimental results show that the method is valid and effective, which can give a more detailed and accurate description for the liquid film in annular flows. Ting Xue, Xiaokang Lin, and Liuxiangzi Yang Copyright © 2016 Ting Xue et al. All rights reserved. Modeling and Calculation of Dent Based on Pipeline Bending Strain Tue, 16 Aug 2016 07:05:42 +0000 http://www.hindawi.com/journals/js/2016/8126214/ The bending strain of long-distance oil and gas pipelines can be calculated by the in-line inspection tool which used inertial measurement unit (IMU). The bending strain is used to evaluate the strain and displacement of the pipeline. During the bending strain inspection, the dent existing in the pipeline can affect the bending strain data as well. This paper presents a novel method to model and calculate the pipeline dent based on the bending strain. The technique takes inertial mapping data from in-line inspection and calculates depth of dent in the pipeline using Bayesian statistical theory and neural network. To verify accuracy of the proposed method, an in-line inspection tool is used to inspect pipeline to gather data. The calculation of dent shows the method is accurate for the dent, and the mean relative error is 2.44%. The new method provides not only strain of the pipeline dent but also the depth of dent. It is more benefit for integrity management of pipeline for the safety of the pipeline. Qingshan Feng, Rui Li, and Hong Zhang Copyright © 2016 Qingshan Feng et al. All rights reserved. Piezoelectric Wind Energy Harvesting from Self-Excited Vibration of Square Cylinder Sun, 14 Aug 2016 13:22:49 +0000 http://www.hindawi.com/journals/js/2016/2353517/ Self-excited vibration of a square cylinder has been considered as an effective way in harvesting piezoelectric wind energy. In present work, both of the vortex-induced vibration and unstable galloping phenomenon process are investigated in a reduced velocity () range of with load resistance ranging in  MΩ. The vortex-induced vibration covers presynchronization, synchronization, and postsynchronization branches. An aeroelectromechanical model is given to describe the coupling of the dynamic equation of the fluid-structure interaction and the equation of Gauss law. The effects of load resistance are investigated in both the open-circuit and close-circuit system by a linear analysis, which covers the parameters of the transverse displacement, aerodynamic force, output voltage, and harvested power utilized to measure the efficiency of the system. The highest level of the transverse displacement and the maximum value of harvested power of synchronization branch during the vortex-induced vibration and galloping are obtained. The results show that the large-amplitude galloping at high wind speeds can generate energy. Additionally, energy can be harvested by utilization of the lock-in phenomenon of vortex-induced vibration under low wind speed. Junlei Wang, Sheng Wen, Xingqiang Zhao, Min Zhang, and Jingyu Ran Copyright © 2016 Junlei Wang et al. All rights reserved. Determine the Foot Strike Pattern Using Inertial Sensors Thu, 11 Aug 2016 10:33:07 +0000 http://www.hindawi.com/journals/js/2016/4759626/ From biomechanical point of view, strike pattern plays an important role in preventing potential injury risk in running. Traditionally, strike pattern determination was conducted by using 3D motion analysis system with cameras. However, the procedure is costly and not convenient. With the rapid development of technology, sensors have been applied in sport science field lately. Therefore, this study was designed to determine the algorithm that can identify landing strategies with a wearable sensor. Six healthy male participants were recruited to perform heel and forefoot strike strategies at 7, 10, and 13 km/h speeds. The kinematic data were collected by Vicon 3D motion analysis system and 2 inertial measurement units (IMU) attached on the dorsal side of both shoes. The data of each foot strike were gathered for pitch angle and strike index analysis. Comparing the strike index from IMU with the pitch angle from Vicon system, our results showed that both signals exhibited highly correlated changes between different strike patterns in the sagittal plane (). Based on the findings, the IMU sensors showed potential capabilities and could be extended beyond the context of sport science to other fields, including clinical applications. Tzyy-Yuang Shiang, Tsung-Yu Hsieh, Yin-Shin Lee, Chen-Chi Wu, Meng-Chieh Yu, Chung-Huan Mei, and I-Han Tai Copyright © 2016 Tzyy-Yuang Shiang et al. All rights reserved. Underwater Object Tracking Using Sonar and USBL Measurements Wed, 10 Aug 2016 07:54:26 +0000 http://www.hindawi.com/journals/js/2016/8070286/ In the scenario where an underwater vehicle tracks an underwater target, reliable estimation of the target position is required. While USBL measurements provide target position measurements at low but regular update rate, multibeam sonar imagery gives high precision measurements but in a limited field of view. This paper describes the development of the tracking filter that fuses USBL and processed sonar image measurements for tracking underwater targets for the purpose of obtaining reliable tracking estimates at steady rate, even in cases when either sonar or USBL measurements are not available or are faulty. The proposed algorithms significantly increase safety in scenarios where underwater vehicle has to maneuver in close vicinity to human diver who emits air bubbles that can deteriorate tracking performance. In addition to the tracking filter development, special attention is devoted to adaptation of the region of interest within the sonar image by using tracking filter covariance transformation for the purpose of improving detection and avoiding false sonar measurements. Developed algorithms are tested on real experimental data obtained in field conditions. Statistical analysis shows superior performance of the proposed filter compared to conventional tracking using pure USBL or sonar measurements. Filip Mandić, Ivor Rendulić, Nikola Mišković, and Đula Nađ Copyright © 2016 Filip Mandić et al. All rights reserved. Estimation of Individual Cylinder Air-Fuel Ratio in Gasoline Engine with Output Delay Wed, 10 Aug 2016 07:52:44 +0000 http://www.hindawi.com/journals/js/2016/5908459/ The estimation of the individual cylinder air-fuel ratio (AFR) with a single universal exhaust gas oxygen (UEGO) sensor installed in the exhaust pipe is an important issue for the cylinder-to-cylinder AFR balancing control, which can provide high-quality torque generation and reduce emissions in multicylinder engine. In this paper, the system dynamic for the gas in exhaust pipe including the gas mixing, gas transport, and sensor dynamics is described as an output delay system, and a new method using the output delay system observer is developed to estimate the individual cylinder AFR. With the AFR at confluence point augmented as a system state, an observer for the augmented discrete system with output delay is designed to estimate the AFR at confluence point. Using the gas mixing model, a method with the designed observer to estimate the individual cylinder AFR is presented. The validity of the proposed method is verified by the simulation results from a spark ignition gasoline engine from engine software enDYNA by Tesis. Changhui Wang and Zhiyuan Liu Copyright © 2016 Changhui Wang and Zhiyuan Liu. All rights reserved. Development of Low-Noise Small-Area 24 GHz CMOS Radar Sensor Tue, 09 Aug 2016 14:20:05 +0000 http://www.hindawi.com/journals/js/2016/8534198/ We present a low-noise small-area 24 GHz CMOS radar sensor for automotive collision avoidance. This sensor is based on direct-conversion pulsed-radar architecture. The proposed circuit is implemented using TSMC 0.13 μm RF (radio frequency) CMOS ( GHz) technology, and it is powered by a 1.5 V supply. This circuit uses transmission lines to reduce total chip size instead of real bulky inductors for input and output impedance matching. The layout techniques for RF are used to reduce parasitic capacitance at the band of 24 GHz. The proposed sensor has low cost and low power dissipation since it is realized using CMOS process. The proposed sensor showed the lowest noise figure of 2.9 dB and the highest conversion gain of 40.2 dB as compared to recently reported research results. It also showed small chip size of 0.56 mm2, low power dissipation of 39.5 mW, and wide operating temperature range of −40 to +125°C. Min Yoon and Jee-Youl Ryu Copyright © 2016 Min Yoon and Jee-Youl Ryu. All rights reserved. AR-RBFS: Aware-Routing Protocol Based on Recursive Best-First Search Algorithm for Wireless Sensor Networks Tue, 09 Aug 2016 11:57:20 +0000 http://www.hindawi.com/journals/js/2016/8743927/ Energy issue is one of the most important problems in wireless sensor networks. They consist of low-power sensor nodes and a few base station nodes. They must be adaptive and efficient in data transmission to sink in various areas. This paper proposes an aware-routing protocol based on clustering and recursive search approaches. The paper focuses on the energy efficiency issue with various measures such as prolonging network lifetime along with reducing energy consumption in the sensor nodes and increasing the system reliability. Our proposed protocol consists of two phases. In the first phase (network development phase), the sensors are placed into virtual layers. The second phase (data transmission) is related to routes discovery and data transferring so it is based on virtual-based Classic-RBFS algorithm in the lake of energy problem environments but, in the nonchargeable environments, all nodes in each layer can be modeled as a random graph and then begin to be managed by the duty cycle method. Additionally, the protocol uses new topology control, data aggregation, and sleep/wake-up schemas for energy saving in the network. The simulation results show that the proposed protocol is optimal in the network lifetime and packet delivery parameters according to the present protocols. Farzad Kiani Copyright © 2016 Farzad Kiani. All rights reserved. An Improved μTESLA Protocol Based on Queuing Theory and Benaloh-Leichter SSS in WSNs Tue, 09 Aug 2016 10:23:35 +0000 http://www.hindawi.com/journals/js/2016/9021650/ Broadcast authentication is a fundamental security technology in wireless sensor networks (ab. WSNs). As an authentication protocol, the most widely used in WSN, μTESLA protocol, its publication of key is based on a fixed time interval, which may lead to unsatisfactory performance under the unstable network traffic environment. Furthermore, the frequent network communication will cause the delay authentication for some broadcast packets while the infrequent one will increase the overhead of key computation. To solve these problems, this paper improves the traditional μTESLA by determining the publication of broadcast key based on the network data flow rather than the fixed time interval. Meanwhile, aiming at the finite length of hash chain and the problem of exhaustion, a self-renewal hash chain based on Benaloh-Leichter secret sharing scheme (SRHC-BL SSS) is designed, which can prolong the lifetime of network. Moreover, by introducing the queue theory model, we demonstrate that our scheme has much lower key consumption than μTESLA through simulation evaluations. Finally, we analyze and prove the security and efficiency of the proposed self-renewal hash chain, comparing with other typical schemes. Haiping Huang, Tianhe Gong, Tao Chen, Mingliang Xiong, Xinxing Pan, and Ting Dai Copyright © 2016 Haiping Huang et al. All rights reserved. Optimized Design and Calibration of the Triaxis Induction Magnetometer with Crosstalk and Nonorthogonality Compensation Mon, 08 Aug 2016 11:38:43 +0000 http://www.hindawi.com/journals/js/2016/1810636/ An optimized triaxis induction magnetometer has been designed and calibrated to minimize the influences from the nonorthogonality and the magnetic flux crosstalk. Utilizing the nonlinear least square method, contributions due to the nonorthogonal assembly of three transducers are cancelled. The magnetic flux crosstalk is a frequency-dependent error component in the calibration of the triaxis induction magnetometer. Influences from the assembly density, the frequency, and the feedback amount are analyzed theoretically, and an optimized sensor configuration which has a smaller crosstalk is achieved. Moreover, a mathematical compensation algorithm has also been utilized to suppress the residues crosstalk ulteriorly. To validate the theoretical analysis, a triaxis induction magnetometer was manufactured and the experiment setup has also been built. The experiment results show that the cross-outputs of the transverse induction magnetometers have been significantly decreased about two orders, indicating that the proposed method is applicable for the triaxis induction magnetometer. Hongyu Shi, Yanzhang Wang, and Jun Lin Copyright © 2016 Hongyu Shi et al. All rights reserved. Disjoint Key Establishment Protocol for Wireless Sensor and Actor Networks Sun, 07 Aug 2016 13:17:23 +0000 http://www.hindawi.com/journals/js/2016/5071617/ Key distribution is essential for providing secure communication between commercial and sensitive applications of wireless sensor and actor networks (WSANs). It becomes more challenging when any of the intermediate sensor nodes is compromised by the adversaries as the messages carrying secure keys will be exposed and links will be unreliable. This paper presents a Disjoint Key Establishment Protocol (DKEP) that does not require transmitting keys across the nodes. In DKEP, each node is preloaded with one row and one column from a matrix. After the deployment, indices for row and column are exchanged between the two nodes and values at intersection of row and column index will be used to calculate the key on each node. DKEP is verified by performing formal analysis using Rubin Logic and validated using simulations in NS-2. Simulation results demonstrate the effectiveness and efficiency of DKEP compared to contemporary schemes in terms of reducing storage and communication cost and improving resilience against node compromise attacks. Moreover, the proposed scheme is implemented in a group-based mobile application scenario for secure message exchange. AtaUllah Ghafoor, Muhammad Sher, Muhammad Imran, and Imran Baig Copyright © 2016 AtaUllah Ghafoor et al. All rights reserved. Attitude Estimation Using Kalman Filtering: External Acceleration Compensation Considerations Sun, 07 Aug 2016 09:48:28 +0000 http://www.hindawi.com/journals/js/2016/6943040/ Attitude estimation is often inaccurate during highly dynamic motion due to the external acceleration. This paper proposes extended Kalman filter-based attitude estimation using a new algorithm to overcome the external acceleration. This algorithm is based on an external acceleration compensation model to be used as a modifying parameter in adjusting the measurement noise covariance matrix of the extended Kalman filter. The experiment was conducted to verify the estimation accuracy, that is, one-axis and multiple axes sensor movement. Five approaches were used to test the estimation of the attitude: (1) the KF-based model without compensating for external acceleration, (2) the proposed KF-based model which employs the external acceleration compensation model, (3) the two-step KF using weighted-based switching approach, (4) the KF-based model which uses the threshold-based approach, and (5) the KF-based model which uses the threshold-based approach combined with a softened part approach. The proposed algorithm showed high effectiveness during the one-axis test. When the testing conditions employed multiple axes, the estimation accuracy increased using the proposed approach and exhibited external acceleration rejection at the right timing. The proposed algorithm has fewer parameters that need to be set at the expense of the sharpness of signal edge transition. Romy Budhi Widodo and Chikamune Wada Copyright © 2016 Romy Budhi Widodo and Chikamune Wada. All rights reserved. Research on Application of Wax Deposition Detection in the Nonmetallic Pipeline Based on Electrical Capacitance Tomography Sun, 07 Aug 2016 07:42:01 +0000 http://www.hindawi.com/journals/js/2016/7390470/ Wax deposition detection in nonmetallic pipelines is an important requirement in the oil industry. In this paper, an ECT (electrical capacitance tomography) sensor is developed for wax deposition detection in nonmetallic pipelines. Four wax models with different concentrations were established for detection. These models were analyzed through simulations and practical experiments simultaneously and data were compared. A linear back projection algorithm is applied to reconstruct the image with both simulated and experimental data. A comparison of binary images with different concentration of stratified flow was demonstrated; this illustrates that the difference in concentration between the experimental results and profile distribution is less than 1.2%. The experimental results indicate that the ECT system is valid and feasible for detecting the degree of wax deposition in the nonmetallic pipelines. Nan Li, Kui Liu, Xiangdong Yang, and Mingchen Cao Copyright © 2016 Nan Li et al. All rights reserved. Integrated Analysis of the Formation Mechanism of Cracks in a Concrete Dam Using Microseismic Monitoring and Numerical Simulation Thu, 04 Aug 2016 11:23:17 +0000 http://www.hindawi.com/journals/js/2016/5720565/ The dam of Guanyinyan hydropower station is composed of a concrete gravity dam in the left bank and a rockfill dam in the right bank. During the operation of the hydropower station, several surface cracks occurred in the concrete gravity dam, which threatened the stability of the dam. To evaluate the evolution trend of the cracks and forecast the potential risk of the dam, the microseismic (MS) monitoring technique and finite-element method were used. First, the concrete three-point bending field test was performed to prove the reliability of the MS technique in monitoring the concrete cracks. The MS monitoring results were consistent with the simulation results. Then, the MS monitoring system was installed in the dam body. By analysing the MS activities before and after the impoundment, the evolution trend of the cracks and potential risk of the dam were evaluated and forecasted. The simulation results were also consistent with the monitoring results. These results can provide significant references for the operation safety of the dam and also present a new thought for the risk evaluation of similar dam engineering. Gang He, Biao Li, Xuben Wang, and Nuwen Xu Copyright © 2016 Gang He et al. All rights reserved. An Electrical Wave Height Measurement at Spatial Multipoint Locations in Liquid Dampers for Structural Vibration Mitigation Thu, 04 Aug 2016 08:23:55 +0000 http://www.hindawi.com/journals/js/2016/6874125/ Liquid dampers such as tuned liquid column dampers and tuned liquid dampers have been adopted to ensure serviceability of a vibratory building subjected to wind. In order to maximize efficiency of the vibration suppression, tuning frequency of the liquid dampers is supposed to be set to the first natural frequency of the building. Therefore, experimental evaluation of the natural frequency of liquid dampers is a primal factory task prior to their installation at the building. In this study, a novel liquid height measurement system based on variable resistance in an electric field is developed for observation of vertical motion of the liquid dampers. The proposed system can simultaneously measure the liquid height of multipoint locations in the electric field. In the experimental phase, natural frequency of the liquid dampers is experimentally evaluated utilizing the developed system. The performance of the proposed system is verified by comparison with the capacitive type wavemeter. Junhee Kim, Seok-Jung Jang, and Kyung-Won Min Copyright © 2016 Junhee Kim et al. All rights reserved. Multipath Load Balancing Routing for Internet of Things Wed, 03 Aug 2016 14:02:21 +0000 http://www.hindawi.com/journals/js/2016/4250746/ In the next-generation technology, Internet of Things (IoT), billions of smart objects will communicate with one another to make human lives more convenient. IoT is based on wireless sensor network (WSN), and Zigbee is one of the most popular WSN protocols. A mature IoT environment involves heavy WSN data transmission causing bottleneck problems. However, Zigbee’s AODV routing stack does not have load balance mechanism to handle bursty traffic. Therefore, we develop Multipath Load Balancing (MLB) Routing to substitute Zigbee’s AODV routing. Our proposed MLB consists of two main designs: LAYER_DESIGN and LOAD_BALANCE. LAYER_DESIGN assigns nodes into different layers based on node distance to IoT gateway. Nodes can have multiple next-hops delivering IoT data. All neighboring layer nodes exchange flow information containing current load, used by LOAD_BALANCE to estimate future load of next-hops. With MLB, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balance and avoid bottlenecks. Compared with Zigbee’s AODV and multipath version AODV (AOMDV), experiment results demonstrate that MLB achieves better load balance, lower packet loss rate, and better routing connectivity ratio in both grid and random uniform topologies. MLB provides a more convincing routing solution for IoT applications. Chinyang Henry Tseng Copyright © 2016 Chinyang Henry Tseng. All rights reserved. Compressed Sensing, Pseudodictionary-Based, Superresolution Reconstruction Wed, 03 Aug 2016 07:53:34 +0000 http://www.hindawi.com/journals/js/2016/1250538/ The spatial resolution of digital images is the critical factor that affects photogrammetry precision. Single-frame, superresolution, image reconstruction is a typical underdetermined, inverse problem. To solve this type of problem, a compressive, sensing, pseudodictionary-based, superresolution reconstruction method is proposed in this study. The proposed method achieves pseudodictionary learning with an available low-resolution image and uses the -SVD algorithm, which is based on the sparse characteristics of the digital image. Then, the sparse representation coefficient of the low-resolution image is obtained by solving the norm of minimization problem, and the sparse coefficient and high-resolution pseudodictionary are used to reconstruct image tiles with high resolution. Finally, single-frame-image superresolution reconstruction is achieved. The proposed method is applied to photogrammetric images, and the experimental results indicate that the proposed method effectively increase image resolution, increase image information content, and achieve superresolution reconstruction. The reconstructed results are better than those obtained from traditional interpolation methods in aspect of visual effects and quantitative indicators. Chun-mei Li, Ka-zhong Deng, Jiu-yun Sun, and Hui Wang Copyright © 2016 Chun-mei Li et al. All rights reserved. Design and Simulation Analysis for Integrated Vehicle Chassis-Network Control System Based on CAN Network Tue, 02 Aug 2016 14:36:45 +0000 http://www.hindawi.com/journals/js/2016/7142739/ Due to the different functions of the system used in the vehicle chassis control, the hierarchical control strategy also leads to many kinds of the network topology structure. According to the hierarchical control principle, this research puts forward the integrated control strategy of the chassis based on supervision mechanism. The purpose is to consider how the integrated control architecture affects the control performance of the system after the intervention of CAN network. Based on the principle of hierarchical control and fuzzy control, a fuzzy controller is designed, which is used to monitor and coordinate the ESP, AFS, and ARS. And the IVC system is constructed with the upper supervisory controller and three subcontrol systems on the Simulink platform. The network topology structure of IVC is proposed, and the IVC communication matrix based on CAN network communication is designed. With the common sensors and the subcontrollers as the CAN network independent nodes, the network induced delay and packet loss rate on the system control performance are studied by simulation. The results show that the simulation method can be used for designing the communication network of the vehicle. Wei Yu and Ning Sun Copyright © 2016 Wei Yu and Ning Sun. All rights reserved. Zynq-Based Reconfigurable System for Real-Time Edge Detection of Noisy Video Sequences Tue, 02 Aug 2016 09:47:57 +0000 http://www.hindawi.com/journals/js/2016/2654059/ We implement Zynq-based self-reconfigurable system to perform real-time edge detection of 1080p video sequences. While object edge detection is a fundamental tool in computer vision, noises in the video frames negatively affect edge detection results significantly. Moreover, due to the high computational complexity of 1080p video filtering operations, hardware implementation on reconfigurable hardware fabric is necessary. Here, the proposed embedded system utilizes dynamic reconfiguration capability of Zynq SoC so that partial reconfiguration of different filter bitstreams is performed during run-time according to the detected noise density level in the incoming video frames. Pratt’s Figure of Merit (PFOM) to evaluate the accuracy of edge detection is analyzed for various noise density levels, and we demonstrate that adaptive run-time reconfiguration of the proposed filter bitstreams significantly increases the accuracy of edge detection results while efficiently providing computing power to support real-time processing of 1080p video frames. Performance results on configuration time, CPU usage, and hardware resource utilization are also compared. Iljung Yoon, Heewon Joung, and Jooheung Lee Copyright © 2016 Iljung Yoon et al. All rights reserved.