Journal of Sensors http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Use of Magnetic Fluid in Accelerometers Thu, 18 Dec 2014 09:08:14 +0000 http://www.hindawi.com/journals/js/2014/375623/ Magnetic fluid accelerometer is designed based on the special physical properties of magnetic fluid. Compared with the conventional acceleration sensors, magnetic fluid accelerometer has stronger shock resistance capability, higher sensitivity, lower energy consumption, and better performance in low frequency response. It satisfies the growing requirements of acceleration sensors. In this paper, the dynamic model and the theory of magnetic fluid accelerometers were presented. The structure characteristics of typical magnetic fluid accelerometers were investigated, and the development trend of magnetic fluid accelerometers in the future was also predicted. Besides, a novel accelerometer with linearity better than 1.5% and sensitivity better than 75 mV/g was proposed. Leping Qian and Decai Li Copyright © 2014 Leping Qian and Decai Li. All rights reserved. A Novel Subnanosecond Monocycle Pulse Generator for UWB Radar Applications Mon, 15 Dec 2014 13:57:35 +0000 http://www.hindawi.com/journals/js/2014/150549/ A novel ultra-wideband (UWB) monocycle pulse generator with good performance is designed and demonstrated in this paper. It contains a power supply circuit, a pulse drive circuit, a unique pulse forming circuit, and a novel monopolar-to-monocycle pulse transition circuit. The drive circuit employs wideband bipolar junction transistors (BJTs) and linear power amplifier transistor to produce a high amplitude drive pulse, and the pulse forming circuit uses the transition characteristics of step recovery diode (SRD) effectively to produce a negative narrow pulse. At last, the monocycle pulse forming circuit utilizes a novel inductance L short-circuited stub to generate the monocycle pulse directly. Measurement results show that the waveform of the generated monocycle pulses is over 76 V in peak-to-peak amplitude and 3.2 ns in pulse full-width. These characteristics of the monocycle pulse are advantageous for obtaining long detection range and high resolution, when it is applied to ultra-wideband radar applications. Xinfan Xia, Lihua Liu, Shengbo Ye, Hongfei Guan, and Guangyou Fang Copyright © 2014 Xinfan Xia et al. All rights reserved. Frequency Tuning of Work Modes in Z-Axis Dual-Mass Silicon Microgyroscope Mon, 15 Dec 2014 12:54:22 +0000 http://www.hindawi.com/journals/js/2014/891735/ Frequency tuning of work modes in the silicon vibratory gyroscope is studied by the theoretical, numerical, and experimental methods in this paper. First, the schematic structure and simplified kinematics model of the gyroscope were presented for deducing the natural frequencies. Then, the width and length of support beams were optimized to tune work frequencies at their designed value. Besides, the frequency difference was experimentally tested and manually tuned by varying the voltage applied on the tuning capacitors. The test on a prototype showed that the difference could be localized between −55.8 Hz and 160.2 Hz when the tuning voltage limit is 20 V. Finally, a frequency control loop was developed to automatically tune the sense frequency toward the drive frequency. Both the theoretical analysis and numeric simulation show that the difference is stabilized at 0.8 Hz when no Coriolis force or quadrature coupling force is applied. It is proved that the frequency difference is successfully tuned by modifying the size of support beams before fabrication as well as the voltage applied on the tuning capacitors after fabrication. The automatic tuning loop, used to match the work modes, is beneficial to enhance the performance of the gyroscope as well as its resistance to environment disturbances. Lu Xu, Hongsheng Li, Yunfang Ni, Jia Liu, and Libin Huang Copyright © 2014 Lu Xu et al. All rights reserved. BeTrust: A Dynamic Trust Model Based on Bayesian Inference and Tsallis Entropy for Medical Sensor Networks Wed, 03 Dec 2014 00:10:12 +0000 http://www.hindawi.com/journals/js/2014/649392/ With the rapid development and application of medical sensor networks, the security has become a big challenge to be resolved. Trust mechanism as a method of “soft security” has been proposed to guarantee the network security. Trust models to compute the trustworthiness of single node and each path are constructed, respectively, in this paper. For the trust relationship between nodes, trust value in every interval is quantified based on Bayesian inference. A node estimates the parameters of prior distribution by using the collected recommendation information and obtains the posterior distribution combined with direct interactions. Further, the weights of trust values are allocated through using the ordered weighted vector twice and overall trust degree is represented. With the associated properties of Tsallis entropy, the definition of path Tsallis entropy is put forward, which can comprehensively measure the uncertainty of each path. Then a method to calculate the credibility of each path is derived. The simulation results show that the proposed models can correctly reflect the dynamic of node behavior, quickly identify the malicious attacks, and effectively avoid such path containing low-trust nodes so as to enhance the robustness. Yan Gao and Wenfen Liu Copyright © 2014 Yan Gao and Wenfen Liu. All rights reserved. Boundary Detection Method for Large-Scale Coverage Holes in Wireless Sensor Network Based on Minimum Critical Threshold Constraint Mon, 01 Dec 2014 06:50:45 +0000 http://www.hindawi.com/journals/js/2014/985854/ The existing coverage hole boundary detection methods cannot detect large-scale coverage hole boundary in wireless sensor network quickly and efficiently. Aiming at this problem, a boundary detection method for large-scale coverage holes in wireless sensor network based on minimum critical threshold constraint is proposed. Firstly, the optimization problem of minimum critical threshold is highlighted, and its formulaic description is constructed according to probabilistic sensing model. On the basis of this, the distributed gradient information is used to approximately solve the optimization problem. After that, local-scale rough boundary detection algorithm incorporating the minimum critical threshold and its iterative thinning algorithm are proposed according to blocking flow theory. The experimental results show that the proposed method has low computational complexity and network overhead when detecting large-scale coverage hole boundary in wireless sensor network. Rong Jing, Lingfu Kong, and Liang Kong Copyright © 2014 Rong Jing et al. All rights reserved. TDAL: Thoroughly Data Aggregation of Low Energy Devices in Secure Heterogeneous Wireless Sensor Networks Thu, 27 Nov 2014 12:35:30 +0000 http://www.hindawi.com/journals/js/2014/938480/ The heterogeneous wireless sensor networks (HWSNs), composed of multiple types of tiny devices (sensor nodes) with wireless communication capability and suffering from computational resources constrains, enable interacting with the physical world, like never before. Innovative applications are developed for security, industrial production, monitoring, and tracking, but theoretical assumptions on these distributed data may not hold in a real scenario. In this paper, the emphasis is on accurate data and sensor nodes privacy preserving while transmitting their sensory information amongst neighbors toward the sink based on parent-child relationship in the wireless sensor network (WSN) environment, while ensuring energy saving. Data aggregation is a known energy efficient technique that is investigated through in-depth analysis of sensor communication through game theory, considering various embodiments of methods like elliptic curve cryptography for secrecy between nodes. This paper endeavors to provide new perspective for secure and energy efficient data aggregation models, where the heterogeneity of a sensor network environment makes it more complex to predict the overall network outputs. Tristan Daladier Engouang, Yun Liu, and Zhenjiang Zhang Copyright © 2014 Tristan Daladier Engouang et al. All rights reserved. Long-Stroke Nanopositioning Stage Driven by Piezoelectric Motor Mon, 24 Nov 2014 08:34:02 +0000 http://www.hindawi.com/journals/js/2014/926314/ This paper reported a biaxial nanopositioning stage single-driven by piezoelectric motor. The employed piezoelectric motor can perform two different driving modes, namely, AC drive mode to drive in long-stroke and at high-speed and DC scanning mode with the high-resolution of several nanometers, which satisfies the requirements of both long-stroke and nanoresolution. To compensate for the effects of the variable friction force and some unpredictable disturbances, a novel backward error compensation (BEC) positioning control method integrated of the two driving modes and a double closed-loop PID controller system are proposed to obtain a high-accuracy positional motion. The experiment results demonstrate that the nanopositioning stage with large travel range of 300 mm × 300 mm has a fine speed characteristic and resolution is 5 nm. In the experiments of different travels up to 15 mm, calibrated by a commercial laser vibrometer, the positioning accuracy is proved within 55 nm in x-axis and 40 nm in y-axis with standard deviation less than 40 nm in x-axis and 30 nm in y-axis and the final position locking can be limited to 10 nm, meeting the requirements of micromanipulation technology. Yong Wang, Fujun Sun, Junhui Zhu, Ming Pang, and Changhai Ru Copyright © 2014 Yong Wang et al. All rights reserved. FPGA Based Single Chip Solution with 1-Wire Protocol for the Design of Smart Sensor Nodes Sun, 23 Nov 2014 08:18:16 +0000 http://www.hindawi.com/journals/js/2014/125874/ Applications that involve monitoring of water quality parameters require measuring devices to be placed at different geographical locations but are controlled centrally at a remote site. The measuring devices in such applications need to be small, consume low power, and must be capable of local processing tasks facilitating the mobility to span the measuring area in a vast geographic area. This paper presents the design of a generalized, low-cost, reconfigurable, reprogrammable smart sensor node using a ZigBee with a Field-Programmable Gate Array (FPGA) that embeds all processing and communication functionalities based on the IEEE 1451 family of standards. Design of the sensor nodes includes processing and transducer control functionalities in a single core increasing the speedup of processing power due to interprocess communication taking place within the chip itself. Results obtained by measuring the pH value and temperature of water samples verify the performance of the proposed sensor node. M. D. R. Perera, R. G. N. Meegama, and M. K. Jayananda Copyright © 2014 M. D. R. Perera et al. All rights reserved. A Portable Random Key Predistribution Scheme for Distributed Sensor Network Mon, 17 Nov 2014 09:53:40 +0000 http://www.hindawi.com/journals/js/2014/394147/ A distributed sensor network (DSN) can be deployed to collect information for military or civilian applications. However, due to the characteristics of DSNs such as limited power, key distribution for a distributed sensor network is complex. In this paper, a neighbor-based path key establishing method and a seed-based algorithm are put forward to improve the original random key pre-distribution scheme. The new scheme is portable because it is independent of the routing protocol. Moreover, the connectivity of the entire network also approaches 1. In particular, the new scheme can keep high connectivity by setting a small amount of redundancy in parameter values when the number of neighbors drops because of the node dormancy or death. The resilience against node capture in our scheme is not lower than that in the -path scheme and the basic schemes when the number of hops in a path is larger than 5, and the simulation result shows that the efficiency of our scheme is also slightly higher. Shihui Zheng, Yuan Tian, Lei Jin, and Yu Yang Copyright © 2014 Shihui Zheng et al. All rights reserved. Effect of a Non-Newtonian Load on Signature for Quartz Crystal Microbalance Measurements Thu, 13 Nov 2014 07:04:59 +0000 http://www.hindawi.com/journals/js/2014/373528/ The quartz crystal microbalance (QCM) is increasingly used for monitoring the interfacial interaction between surfaces and macromolecules such as biomaterials, polymers, and metals. Recent QCM applications deal with several types of liquids with various viscous macromolecule compounds, which behave differently from Newtonian liquids. To properly monitor such interactions, it is crucial to understand the influence of the non-Newtonian fluid on the QCM measurement response. As a quantitative indicator of non-Newtonian behavior, we used the quartz resonator signature, , of the QCM measurement response, which has a consistent value for Newtonian fluids. We then modified De Kee’s non-Newtonian three-parameter model to apply it to our prediction of values for non-Newtonian liquids. As a model, we chose polyethylene glycol (PEG400) with the titration of its volume concentration in deionized water. As the volume concentration of PEG400 increased, the value decreased, confirming that the modified De Kee’s three-parameter model can predict the change in value. Collectively, the findings presented herein enable the application of the quartz resonator signature, , to verify QCM measurement analysis in relation to a wide range of experimental subjects that may exhibit non-Newtonian behavior, including polymers and biomaterials. Jae-Hyeok Choi, Kay K. Kanazawa, and Nam-Joon Cho Copyright © 2014 Jae-Hyeok Choi et al. All rights reserved. Using Capacitance Sensor to Extract Characteristic Signals of Dozing from Skin Surface Thu, 13 Nov 2014 06:57:28 +0000 http://www.hindawi.com/journals/js/2014/238350/ Skin is the largest organ of the human body and a physiological structure that is directly exposed to the environment. From a theoretical perspective, numerous physiological and psychological signals use the skin as a medium for input and output with the outside world. Therefore, the skin is considered an optimal signal interception point when developing noninvasive, direct, and rapid signal exploration devices. To date, skin signal interceptions are predominantly performed by measuring skin impedance. However, this method is prone to interference such as sweat secretion, salt accumulation on the skin, and muscle contractions, which may result in a substantial amount of interference and erroneous results. The present study proposes novel and effective methods for skin signal interception, such as using a nested probe as a sensor to measure capacitance to be further processed as physiological and psychological signals. The experimental results indicate that the capacitance curve for the transition between wakefulness and dozing exhibits significant changes. This change in the curve can be analyzed by computer programs to clearly and rapidly determine whether the subject has entered the initial phases of sleep. Po-Ying Chen, Chi-Chang Chen, Wen-Kuan Yeh, Yukan Chang, Der-Chen Huang, Shyr-Shen Yu, Chwei-Shyong Tsai, Yu-Jung Huang, Wei-Cheng Lin, Shao-I Chu, Chung-Long Pan, Tsung-Hung Lin, and Shyh-Chang Liu Copyright © 2014 Po-Ying Chen et al. All rights reserved. Development of Prototype Laboratory Setup for Selective Detection of Ethylene Based on Multiwalled Carbon Nanotubes Thu, 06 Nov 2014 07:15:55 +0000 http://www.hindawi.com/journals/js/2014/395035/ We report here a prototype laboratory setup for detecting ethylene (C2H4) in ppm level employing a sensor made of multiwalled carbon nanotubes of 40 nm average tube diameter. The proposed reversible chemoresistive ethylene sensor is fabricated using Kapton as the substrate onto which carbon nanotubes are coated using thick film technology. IDT silver electrodes are printed using piezo head based ink-jet printing technology. The increases in electrical resistance of the sensor element are measured on exposure to ethylene for different ethylene concentrations using a potentiostat and data acquisition system. The increase in resistance of the calibrated sensor element on exposure to ethylene (analyte) is about 18.4% at room temperature for 50 ppm ethylene concentration. This change is reversible. Our sensor element exhibits a better performance than those reported earlier (1.8%) and it has got the rise and fall time of 10 s and 60 s, respectively. It could be used for testing the ripening of fruits. J. Kathirvelan and R. Vijayaraghavan Copyright © 2014 J. Kathirvelan and R. Vijayaraghavan. All rights reserved. A Hybrid Structural Health Monitoring System for the Detection and Localization of Damage in Composite Structures Wed, 29 Oct 2014 12:11:00 +0000 http://www.hindawi.com/journals/js/2014/109403/ A hybrid structural health monitoring (SHM) system, consisting of a piezoelectric transducer and fiber optic sensors (FOS) for generating and monitoring Lamb waves, was investigated to determine their potential for damage detection and localization in composite aerospace structures. As part of this study, the proposed hybrid SHM system, together with an in-house developed algorithm, was evaluated to detect and localize two types of damage: a through thickness damage (hole of 2 mm in diameter) and a surface damage (2 mm diameter bore hole with a depth of 0.65 mm) located on the backside of the plate. The experiments were performed using an aircraft representative composite plate skin, manufactured from carbon fiber reinforced polymer (CFRP). Darun Barazanchy, Marcias Martinez, Bruno Rocha, and Marko Yanishevsky Copyright © 2014 Darun Barazanchy et al. All rights reserved. TerraSAR-X StripMap Data Interpretation of Complex Urban Scenarios with 3D SAR Tomography Wed, 29 Oct 2014 08:26:16 +0000 http://www.hindawi.com/journals/js/2014/386753/ The severe layover problem of complex urban scenarios in SAR data makes SAR data interpretation very difficult, especially for nonexperts. In this paper, we use 3D SAR tomography for SAR data interpretation of dense urban areas. An efficient and robust approach named Butterworth-filter based singular value decomposition (BSVD) is used for tomographic analysis. Two typical dense urban areas of interest located in Shanghai are analyzed. The tomographic results could help users to better understand the backscattering scenario. The experimental results indicate that SAR tomography is a promising and effective way to facilitate SAR data interpretation of complex urban areas. Lianhuan Wei, Timo Balz, Mingsheng Liao, and Lu Zhang Copyright © 2014 Lianhuan Wei et al. All rights reserved. An Improved FastSLAM System Based on Distributed Structure for Autonomous Robot Navigation Mon, 27 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/js/2014/456289/ Fast simultaneous localization and mapping (FastSLAM) is an efficient algorithm for autonomous navigation of mobile vehicle. However, FastSLAM must reconfigure the entire vehicle state equation when the feature points change, which causes an exponential growth in quantities of computation and difficulties in isolating potential faults. In order to overcome these limitations, an improved FastSLAM, based on the distributed structure, is developed in this paper. There are two state estimation parts designed in this improved FastSLAM. Firstly, a distributed unscented particle filter is used to avoid reconfiguring the entire system equation in the vehicle state estimation part. Secondly, in the landmarks estimation part, the observation model is designed as a linear one to update the landmarks states by using the linear observation errors. Then, the convergence of the proposed and improved FastSLAM algorithm is given in the sense of mean square. Finally, the simulation results show that the proposed distributed algorithm could reduce the computational complexity with high accuracy and high fault-tolerance performance. Fu-jun Pei, Hao-yang Li, and Yu-hang Cheng Copyright © 2014 Fu-jun Pei et al. All rights reserved. Multimedia Fusion for Public Security in Heterogeneous Sensor Networks Mon, 27 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/js/2014/273210/ Public security is a widespread disastrous phenomenon that constitutes a grave threat. Although information fusion of video sensor networks for public security has been studied extensively, multimedia fusion in heterogeneous sensor networks or its application in public security remains a challenge and central goal in the field of information fusion. In this study, to realize the detection, monitoring, and intelligent alarm of such hazards, we develop a graph-based real-time schema for studying the dynamic structure of heterogeneous sensors for public security. In the proposed schema, data fusion algorithms based on data-driven aspects of fusion are explored to locate the optimal sensing ranges of sensor nodes in a network with heterogeneous targets. In addition, we propose a framework incorporating useful contextual and temporal cues for public security alarm, explore its conceptualizations, benefits, and challenges, and analyze the correlations of the target motion elements in the multimedia sensor stream. The experimental results show that the new method offers a better way of intelligent alarm that cannot be achieved by existing schemes. Jiangfan Feng, Wenwen Zhou, and Kaixin Sun Copyright © 2014 Jiangfan Feng et al. All rights reserved. Live-Load Testing Application Using a Wireless Sensor System and Finite-Element Model Analysis of an Integral Abutment Concrete Girder Bridge Thu, 23 Oct 2014 11:29:06 +0000 http://www.hindawi.com/journals/js/2014/859486/ As part of an investigation on the performance of integral abutment bridges, a single-span, integral abutment, prestressed concrete girder bridge near Perry, Utah was instrumented for live-load testing. The live-load test included driving trucks at 2.24 m/s (5 mph) along predetermined load paths and measuring the corresponding strain and deflection. The measured data was used to validate a finite-element model (FEM) of the bridge. The model showed that the integral abutments were behaving as 94% of a fixed-fixed support. Live-load distribution factors were obtained using this validated model and compared to those calculated in accordance to recommended procedures provided in the AASHTO LRFD Bridge Design Specifications (2010). The results indicated that if the bridge was considered simply supported, the AASHTO LRFD Specification distribution factors were conservative (in comparison to the FEM results). These conservative distribution factors, along with the initial simply supported design assumption resulted in a very conservative bridge design. In addition, a parametric study was conducted by modifying various bridge properties of the validated bridge model, one at a time, in order to investigate the influence that individual changes in span length, deck thickness, edge distance, skew, and fixity had on live-load distribution. The results showed that the bridge properties with the largest influence on bridge live-load distribution were fixity, skew, and changes in edge distance. Robert W. Fausett, Paul J. Barr, and Marvin W. Halling Copyright © 2014 Robert W. Fausett et al. All rights reserved. An Integrated Denoising Method for Sensor Mixed Noises Based on Wavelet Packet Transform and Energy-Correlation Analysis Mon, 20 Oct 2014 08:31:51 +0000 http://www.hindawi.com/journals/js/2014/650891/ In order to solve the problem of industrial sensor signal denoising, an integrated denoising method for sensor mixed noises based on wavelet packet transform and energy-correlation analysis is proposed. The architecture of proposed method is designed and the key technologies, such as wavelet packet transformation, energy-correlation analysis, and processing method of wavelet packet coefficients based on energy-correlation analysis, are presented. Finally, a simulation example for a specific signal and an application of shearer cutting current signal, which mainly contain white Gaussian noise and impact noise, are carried out, and the simulation and application results show that the proposed method is effective and is outperforming others. Chao Tan, Yanping Wang, Xin Zhou, Zhongbin Wang, Lin Zhang, and Xinhua Liu Copyright © 2014 Chao Tan et al. All rights reserved. Depth Measurement Based on Infrared Coded Structured Light Sun, 19 Oct 2014 11:28:08 +0000 http://www.hindawi.com/journals/js/2014/852621/ Depth measurement is a challenging problem in computer vision research. In this study, we first design a new grid pattern and develop a sequence coding and decoding algorithm to process the pattern. Second, we propose a linear fitting algorithm to derive the linear relationship between the object depth and pixel shift. Third, we obtain depth information on an object based on this linear relationship. Moreover, 3D reconstruction is implemented based on Delaunay triangulation algorithm. Finally, we utilize the regularity of the error curves to correct the system errors and improve the measurement accuracy. The experimental results show that the accuracy of depth measurement is related to the step length of moving object. Tong Jia, ZhongXuan Zhou, and HaiHong Gao Copyright © 2014 Tong Jia et al. All rights reserved. An Efficient Data Collection Protocol Based on Multihop Routing and Single-Node Cooperation in Wireless Sensor Networks Wed, 15 Oct 2014 11:25:30 +0000 http://www.hindawi.com/journals/js/2014/186806/ Considering the constrained resource and energy in wireless sensor networks, an efficient data collection protocol named ESCDD which adopts the multihop routing technology and the single-node selection cooperative communication is proposed to make the communication protocol more simple and easy to realize for the large-scale multihop wireless sensor networks. ESCDD uses the greedy strategy and the control information based on RTS/CTS to select forwarding nodes. Then, the hops in the multihop data transmission are reduced. Based on the power control in physical layer and the control frame called CoTS in MAC layer, ESCDD chooses a single cooperative node to perform cooperative transmission. The receiving node adopts maximal ratio combining (MRC) to recover original data. The energy consumption per hop is reduced. Furthermore, the total energy consumption in data collection process is shared by more nodes and the network lifetime is extended. Compared with GeRaF, EERNFS, and REEFG protocol, the simulation results show that ESCDD can effectively reduce the average delay of multihop data transmission, improve the successful delivery rate of data packets, significantly save the energy consumption of network nodes, and make the energy consumption more balanced. Guoqiang Zheng, Bing Li, Jishun Li, Huahong Ma, and Baofeng Ji Copyright © 2014 Guoqiang Zheng et al. All rights reserved. Design of a UHF Antenna for Partial Discharge Detection of Power Equipment Wed, 15 Oct 2014 08:48:46 +0000 http://www.hindawi.com/journals/js/2014/839386/ A single-arm Archimedean spiral antenna that can be directly fed by a 50  coaxial cable is investigated in this study. Every antenna parameter is optimized under simulation to make the antenna work in the ultra-high frequency band. The influence of dielectric materials, feed cone angle, and antenna duty ratio is also examined. Partial discharge (PD) experiments on several typical artificial insulation defects are conducted, and a single-arm Archimedean spiral antenna and a typical microstrip antenna are utilized for PD measurement. The PD characteristics of different insulation defects are also analyzed. Results show that the designed antenna is suitable for ultra-high frequency monitoring. The detection sensitivity of the single-arm spiral antenna is superior to that of the ordinary microstrip antenna. The former can be utilized in wide-band measurement fields. Youyuan Wang, Junfeng Wu, Weigen Chen, and Yajun Wang Copyright © 2014 Youyuan Wang et al. All rights reserved. A Survey on Energy Efficient Wireless Sensor Networks for Bicycle Performance Monitoring Application Mon, 13 Oct 2014 11:41:01 +0000 http://www.hindawi.com/journals/js/2014/153604/ Wireless sensor networks (WSNs) have greatly advanced in the past few decades and are now widely used, especially for remote monitoring; the list of potential uses seems endless. Three types of wireless sensor technologies (Bluetooth, ZigBee, and ANT) have been used to monitor the biomechanical and physiological activities of bicycles and cyclists, respectively. However, the wireless monitoring of these activities has faced some challenges. The aim of this paper is to highlight various methodologies for monitoring cycling to provide an effective and efficient way to overcome the various challenges and limitations of sports cycling using wireless sensor interfaces. Several design criteria were reviewed and compared with different solutions for the implementation of current WSN research, such as low power consumption, long distance communications, small size, and light weight. Conclusions were drawn after observing the example of an advanced and adaptive network technology (ANT) network highlighting reduced power consumption and prolonged battery life. The power saving achieved in the slave node was 88–95% compared to the similar ANT protocol used in the medical rehabilitation. Sadik Kamel Gharghan, Rosdiadee Nordin, and Mahamod Ismail Copyright © 2014 Sadik Kamel Gharghan et al. All rights reserved. Surface Crack Detection for Carbon Fiber Reinforced Plastic Materials Using Pulsed Eddy Current Based on Rectangular Differential Probe Sun, 12 Oct 2014 11:45:13 +0000 http://www.hindawi.com/journals/js/2014/727269/ Aiming at the surface defect inspection of carbon fiber reinforced composite, the differential and the direct measurement finite element simulation models of pulsed eddy current flaw detection were built. The principle of differential pulsed eddy current detection was analyzed and the sensitivity of defect detection was compared through two kinds of measurements. The validity of simulation results was demonstrated by experiments. The simulation and experimental results show that the pulsed eddy current detection method based on rectangular differential probe can effectively improve the sensitivity of surface defect detection of carbon fiber reinforced composite material. Jialong Wu, Deqiang Zhou, and Jun Wang Copyright © 2014 Jialong Wu et al. All rights reserved. Estimation of Displacement and Rotation by Magnetic Tactile Sensor Using Stepwise Regression Analysis Sun, 12 Oct 2014 08:50:01 +0000 http://www.hindawi.com/journals/js/2014/459059/ The human is covered with soft skin and has tactile receptors inside. The skin deforms along a contact surface. The tactile receptors detect the mechanical deformation. The detection of the mechanical deformation is essential for the tactile sensation. We propose a magnetic type tactile sensor which has a soft surface and eight magnetoresistive elements. The soft surface has a permanent magnet inside and the magnetoresistive elements under the soft surface measure the magnetic flux density of the magnet. The tactile sensor estimates the displacement and the rotation on the surface based on the change of the magnetic flux density. Determination of an estimate equation is difficult because the displacement and the rotation are not geometrically decided based on the magnetic flux density. In this paper, a stepwise regression analysis determines the estimate equation. The outputs of the magnetoresistive elements are used as explanatory variables, and the three-axis displacement and the two-axis rotation are response variables in the regression analysis. We confirm the regression analysis is effective for determining the estimate equations through simulation and experiment. The results show the tactile sensor measures both the displacement and the rotation generated on the surface by using the determined equation. Hiroyuki Nakamoto, Taketo Wakabayashi, Futoshi Kobayashi, and Fumio Kojima Copyright © 2014 Hiroyuki Nakamoto et al. All rights reserved. Contactless Inductive Flow Tomography: Brief History and Recent Developments in Its Application to Continuous Casting Wed, 17 Sep 2014 10:46:16 +0000 http://www.hindawi.com/journals/js/2014/739161/ The contactless inductive flow tomography (CIFT) aims at reconstructing the velocity field of electrically conducting fluids, with special focus on applications in metallurgy and crystal growth technologies. The method relies on the induction of secondary magnetic fields if the moving fluid is exposed to a primary magnetic field. The theoretical foundation of the method is delineated, and some early experiments on the reconstruction of the three-dimensional flow in a cylinder are sketched. Then, the recent efforts to apply CIFT to various model problems in connection with the continuous casting of steel are summarized. Matthias Ratajczak, Thomas Gundrum, Frank Stefani, and Thomas Wondrak Copyright © 2014 Matthias Ratajczak et al. All rights reserved. Method of Combining Spectrophotometer and Optical Imaging Equipment to Extract Optical Parameters for Material Rendering Wed, 10 Sep 2014 16:55:48 +0000 http://www.hindawi.com/journals/js/2014/803710/ Optical parameters of materials are used for implementing cinematic rendering in the field of graphics. Critical elements for extracting these optical characteristics are the accuracy of the extracted parameters and the required time for extraction. In this paper, a novel method for improving these elements as well as a comparison to the existing methodology is presented. By using a spectrophotometer and custom designed optical imaging equipment (OIE), our method made it possible to enhance accuracy and accelerate computing speed by reducing the number of unknowns in the fitting equations. Further, we validated the superiority of the extracted optical characteristic parameters with a rendering simulation. Taeyoung Choi, Seonghee Lee, and Seongah Chin Copyright © 2014 Taeyoung Choi et al. All rights reserved. Hybrid Electronic Tongues Applied to the Quality Control of Wines Wed, 10 Sep 2014 07:45:40 +0000 http://www.hindawi.com/journals/js/2014/598317/ The legislation of food industry is becoming increasingly strict with regard to the quality of food products. Therefore, the market is demanding for automatic systems of analysis that allow fast and accurate monitoring of the evolution of quality parameters in agrofood products or permit obtaining information to optimize production processes. In this context, sensors and more specifically microsensors play an important role since they allow fast and reproducible measurement of a large number of quality parameters with good reliability and can be implemented in portable systems. This paper presents a review of the results obtained with an electronic tongue based on different kinds of microsensors applied to wine analysis by the team of IMB-CNM. This multisensor system allows on one hand classifying the wine according to its features like grape variety, geographic origin, year, and organoleptic characteristics and on the other hand quantifying some parameters of interest in quality control, such as alcoholic degree, pH, ions, total acidity, glycerol, and color. Manuel Gutiérrez-Capitán, Fina Capdevila, Jordi Vila-Planas, Carme Domingo, Stephanus Büttgenbach, Andreu Llobera, Anna Puig-Pujol, and Cecilia Jiménez-Jorquera Copyright © 2014 Manuel Gutiérrez-Capitán et al. All rights reserved. Implementation of Mobile Target Positioning Technology Integrating SINS with WSN Measurements Mon, 01 Sep 2014 07:43:21 +0000 http://www.hindawi.com/journals/js/2014/673179/ Accurate and robust positioning technology is expected to promote management level and service efficiency in various industrial applications. The strap-down inertial navigation system (SINS) approach has short-term accurate positioning performance, but the SINS is known for its accumulative error over time. Meanwhile, wireless sensor networks (WSN) approach can keep the mobile target on effective tracking after a long time monitoring, but the WSN may have large positioning error in certain areas. In order to make the positioning method allow profit from their advantages, this paper proposes a positioning technology using SINS approach in conjunction with WSN approach. The measurement parameters by SINS and WSN approaches are used. Then the SINS, anchor nodes, mobile tags, XBee, and computer are applied to design the positioning system. The estimation results indicate that the proposed method can make up for the shortcomings by pure SINS or WSN method and can be available for some accurate and robust applications. Chengming Luo, Wei Li, Hai Yang, Baohua Ying, and Gaifang Xin Copyright © 2014 Chengming Luo et al. All rights reserved. Research on an Improved Method for Permanent Magnet Synchronous Motor Mon, 01 Sep 2014 05:55:28 +0000 http://www.hindawi.com/journals/js/2014/816421/ In permanent magnet synchronous motor (PMSM) traditional vector control system, PI regulator is used in the speed loop, but it has some defects. An improved method of PMSM vector control is proposed in the paper. The active-disturbance rejection control (ADRC) speed regulator is designed with the input signals of given speed and real speed and the output of given stator current q coordinate component. Then, in order to optimize ADRC controller, the least squares support vector machines (LSSVM) optimal regression model is derived and successfully embedded in the ADRC controller. ADRC observation precision and dynamic response of the system are improved. The load disturbance effect on the system is reduced to a large extent. The system anti-interference ability is further improved. Finally, the current sensor CSNE151-100 is selected to sample PMSM stator currents. The voltage sensor JLBV1 is used to sample the stator voltage. The rotor speed of PMSM is measured by mechanical speed sensor, the type of which is BENTLY 330500. Experimental platform is constructed to verify the effectiveness of the proposed method. Yingpei Liu, Tao Gao, and Guo Li Copyright © 2014 Yingpei Liu et al. All rights reserved. Analysis on Structural Stress of 64 × 64 InSb IRFPAs with Temperature Dependent Elastic Underfill Tue, 26 Aug 2014 07:22:35 +0000 http://www.hindawi.com/journals/js/2014/952323/ To improve the reliability of InSb IRFPAs, underfill has usually been filled between InSb chip and Si ROIC. Around the glass transition temperature, underfill shows viscoelasticity, yet, far below it, which shows apparently temperature dependent mechanical properties. Basing on the temperature dependent elastic model of underfill, firstly a small format array of elements InSb IRFPAs is investigated by changing indium bump diameters and heights; simulated results show that the maximum stress in InSb chip has nothing to do with underfill height and is dependent on indium bump diameter; the varying tendency is just like the horizontally extended letter U. When indium bump diameter is set to 24 m with height 21  m, the maximal stress in InSb chip reaches minimum. To learn the stress in elements in short time, with the above optimal structure, InSb IRFPAs array scale is doubled once again from to elements. Simulation results show that the stress maximum in InSb chip is strongly determined by arrays format and increases with array scale; yet, the stress maximum in Si ROIC almost keeps constant and is independent on array sizes; besides, the largest stress locates in InSb chip, and the stress distribution in InSb chip is uniform. Liwen Zhang, Wei Tian, Qingduan Meng, Mengfang Sun, Na Li, and Zhen Lei Copyright © 2014 Liwen Zhang et al. All rights reserved.