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Sensors Journal, IEEE

Issue 9 • Date Sept. 2009

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Displaying Results 1 - 25 of 27
  • [Front cover]

    Publication Year: 2009 , Page(s): C1
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  • IEEE Sensors Journal publication information

    Publication Year: 2009 , Page(s): C2
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  • Table of contents

    Publication Year: 2009 , Page(s): 1005 - 1006
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  • Absolute Phase-Based Distance Measurement for Industrial Monitoring Systems

    Publication Year: 2009 , Page(s): 1007 - 1013
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1070 KB) |  | HTML iconHTML  

    In this paper, principal considerations for a high accuracy millimeter wave (mmw) radar distance measurement system applicable to be used in harsh industrial environments are presented. The system is based on continuous wave (CW) measurement of the reflection coefficient and interpretation of the signal phase. The ambiguity of the phase is overcome by means of a multiple frequency technique. For absolute distance determination, an online calibration procedure is applied. The applicability of the system is underlined by a laboratory demonstrator measurement. View full abstract»

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  • Textile-Based Electrogoniometers for Wearable Posture and Gesture Capture Systems

    Publication Year: 2009 , Page(s): 1014 - 1024
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (837 KB) |  | HTML iconHTML  

    This paper introduces a method for detecting joint angles by using piezoresistive strain sensitive materials, as carbon loaded rubbers are. Materials used can be screen-printed onto fabrics to provide garments with a sensing apparatus able to reconstruct human postures and gestures. The main differences between this approach and the previous ones, and the core of this work, is the rigorous proof that for small local curvatures of the layers the constituting electrogoniometers, the resistance depends only on the total curvature of the layers and not on the particular form that the sensor keeps in adherence with the human body. In this paper, we show that the hypothesis of small local curvature does not severely restrict the set of angles which can be detected. View full abstract»

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  • Microprocessor-Based Temperature Monitoring System Using Optical Fibers

    Publication Year: 2009 , Page(s): 1025 - 1028
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (126 KB) |  | HTML iconHTML  

    This paper describes a microprocessor-based temperature monitoring instrumentation system based on phase modulation principle using interferometric optical sensors system, where the phase of a beam through a temperature sensing fiber (placed in a hot chamber) is compared with that of a beam from a reference fiber placed out side the hot chamber. The sensor system consists of a He-Ne laser source, two beam splitters, two single-mode optical fibers, and two light dependent resistor (LDR)-based timer circuits as detectors. The frequencies of the timer circuits change according to the change in temperature of the hot chamber. A 8085 microprocessor-based system is used to sample the frequencies of the timer circuits. View full abstract»

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  • Robust Deployment of Dynamic Sensor Networks for Cooperative Track Detection

    Publication Year: 2009 , Page(s): 1029 - 1048
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2497 KB) |  | HTML iconHTML  

    The problem of cooperative track detection by a dynamic sensor network arises in many applications, including security and surveillance, and tracking of endangered species. Several authors have recently shown that the quality-of-service of these networks can be statically optimized by placing the sensors in the region of interest (ROI) via mathematical programming. However, if the sensors are subject to external forcing, such as winds or currents, they may be rapidly displaced, and their quality-of-service may be significantly deteriorated over time. The novel approach presented in this paper consists of placing the sensors in the ROI based on their future displacement, which can be estimated from environmental forecasts and sensor dynamic models. The sensor network deployment is viewed as a new problem in dynamic computational geometry, in which the initial positions of a family of circles with time-varying radii and positions are to be optimized subject to sets of algebraic and differential equations. When these equations are nonlinear and time-varying, the optimization problem does not have an exact solution, or global optimum, but can be approximated as a finite-dimensional nonlinear program by discretizing the quality-of-service and the dynamic models with respect to time. Then, a near-optimal solution for the initial sensor positions is sought by means of sequential quadratic programming. The numerical results show that this approach can improve quality-of-service by up to a factor of five compared to existing techniques, and its performance is robust to propagated modeling and deployment errors. View full abstract»

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  • A Log-Antilog Analog Control Circuit for Constant-Power Warm-Thermistor Sensors— Application to Plant Water Status Measurement

    Publication Year: 2009 , Page(s): 1049 - 1057
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1322 KB) |  | HTML iconHTML  

    Warm-thermistor sensors are useful for making measurements of flow and the thermal properties of materials. This paper describes a log-antilog analog control circuit capable of monitoring a thermistor's internal temperature in both ambient temperature sensing mode and self-heating mode, while maintaining infinite precision, wide dynamic range and fast sensor response. A single self-referencing thermistor is used to avoid the problems associated with having to match a thermistor pair in order to obtain an over-temperature signal. Instead, thermistor power levels are switched over a range of 1:1000, allowing measurement of both ambient temperature and heated thermistor temperature during the rise and fall of the heat pulse by a single thermistor at the center of the heat field. This provides a sensitive measurement of the thermal diffusivity and advective properties of the surrounding medium. In this paper, such a sensor is used to investigate the thermal properties of a grapevine cane under conditions of irrigation stress. View full abstract»

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  • Evaluation of a Warm-Thermistor Flow Sensor for Use in Automatic Seepage Meters

    Publication Year: 2009 , Page(s): 1058 - 1067
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1007 KB) |  | HTML iconHTML  

    A warm-thermistor flow sensor is evaluated for use in an automatic seepage meter measuring very slow groundwater inflows into open water bodies. A novel control circuit allows a single self-referencing thermistor to operate with a constant heat output of 36.8 mW, while monitoring the thermistor's internal temperature TS and TF under still-water and flow conditions respectively. The resultant temperature difference TS-TF is the output signal from the instrument. This device is particularly sensitive to very slow fluid flows in the range 0.03 to 3 mm/s, where buoyancy problems have traditionally prevented the use of warm-thermistor flow meters. For flow speeds below 3 mm/s the sensor response was shown in the laboratory to be nearly linear with no offset term. Two flow-calibration setups were investigated; a precision plunging-probe apparatus and a single-step flow calibration system based upon a Hagen-Poiseuille flow regulator and a vertical standpipe. A numerical (CFD) model of the spherical thermistor agreed well with the two experimental calibration procedures over the flow range between 0 and 3 mm/s. The theoretical model - based on the Peclet number - fits the CFD model well between 3 and 100 mm/s, but does not hold true in the buoyancy range below 3 mm/s. For a seepage meter funnel having a bell-to-throat area ratio of 2964, groundwater flow velocities as low as 0.01 mum/s (0.9 mm/day) could be measured using this sensor. View full abstract»

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  • MEMS-Based Selective Preconcentration of Trace Level Breath Analytes

    Publication Year: 2009 , Page(s): 1068 - 1075
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1687 KB) |  | HTML iconHTML  

    This paper presents high-performance micropreconcentrators (muPCs) aimed at breath analysis and a method for eliminating unwanted species from breath samples by using a two-step preconcentration procedure. The muPC consists of embedded high aspect-ratio three-dimensional (3-D) micro pillars coated with an adsorbent polymer. The silicon-glass die has outer dimensions of 7 mm times 7 mm, total inner surface area of ~ 10 m2, and a total inner volume of ~ 6.5 muL. The muPC has on-chip thermal desorption capability and comprises more than 3500 micro pillars with dimensions of 30 mum times 120 mum times 240 mum. The preconcentration factor of the presented muPCs was measured to be above 10 000. Results showed the possibility of selective preconcentration by cascading multiple muPCs with temperature and flow control. The work presented here has profound implications for handheld point-of-care breath analysis instrumentation by first concentrating trace levels of VOCs found in human breath undergoing anesthesia such as n-decane (C10), n-dodecane (C12), 2,6-diisopropylphenol (Propofol), n-tetradecane (C14), and n-hexadecane (C16). Second, it succeeded in eliminating water-like solvent (1-propanol) from the sample to be analyzed. Third, it selectively preconcentrated target compound such as Propofol which is used for medical procedures. The relative concentration of Propofol to C14 was changed from 50% (with one muPC ) to 99.8% (with cascaded muPC). The water-like solvent was also eliminated by 99.9%. View full abstract»

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  • Velocity Profile Measurement Using Digital Signal Processor-Based Optical Tomography System

    Publication Year: 2009 , Page(s): 1076 - 1083
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (805 KB) |  | HTML iconHTML  

    The utilization of personal computer together with data acquisition system (DAS) as the processing tool in optical tomography systems has been a norm ever since the beginning of process tomography. However, the advancements in silicon fabrication technology nowadays allow the fabrication of powerful digital signal processors (DSPS) at a reasonable cost. This allows the technology to be applied in optical tomography system since data acquisition and processing can be performed within the DSP. Thus, the dependency of personal computer and the DAS to sample and process the external signals can be reduced or otherwise eliminated. The DSP system was customized to control the data acquisition process of 16 times 16 optical sensors array, arranged in parallel beam projection. The data collected was used to measure the velocity profile using sensor to sensor cross-correlation and pixel to pixel cross correlation. View full abstract»

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  • Single-Photon Avalanche Diode CMOS Sensor for Time-Resolved Fluorescence Measurements

    Publication Year: 2009 , Page(s): 1084 - 1090
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1095 KB) |  | HTML iconHTML  

    A single-photon avalanche diode-based pixel array for the analysis of fluorescence phenomena is presented. Each 180 times 150 - mum2 pixel integrates a single photon detector combined with an active quenching circuit and a 17-bit digital events counter. On-chip master logic provides the digital control phases required by the pixel array with a full programmability of the main timing synchronisms. The pixel exhibits an average dark count rate of 3 kcps and a dynamic range of over 120-dB in time uncorrelated operation. A complete characterization of the single photon avalanche diode characteristics is reported. Time-resolved fluorescence measurements have been demonstrated by detecting the fluorescence decay of quantum-dot samples without the aid of any optical filters for excitation laser light cutoff. View full abstract»

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  • Detection of S. Typhimirium and Bacillus Anthracis Spores in a Flow System Using ME Biosensors by Optimizing Phage Chemistry

    Publication Year: 2009 , Page(s): 1091 - 1097
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2362 KB) |  | HTML iconHTML  

    This paper presents the results of a study that investigates the optimization of phage chemistry during the fabrication of magnetoelastic (ME) biosensors for the detection of Salmonella typhimurium or Bacillus anthracis spores. The bundling characteristics of the phage filaments limit the ability of the biosensor to bind bacterial cells/spores. Experiments were performed to determine the proper phage concentration for the prevention of bundling in aqueous environments. Based on the transmission electron microscopy (TEM) and scanning electron microscopy (SEM) results, which verify the structure of phage under different concentrations and binding numbers of target species to the sensor surface, we found that phage concentrations of 1011 vir/ml exhibit the best sensor performance in terms of binding sensitivity. Additionally, the sensors immobilized with phage under this condition were tested in a flowing liquid system using S. typhimurium and B. anthracis spores suspensions in concentrations ranging from 5 times101 to 5 times 108 cfu/ml, separately. As cells/spores are bound to a ME biosensor surface, the additional mass of the spores causes a decrease in the resonance frequency of the sensor. The frequency response curves of the ME biosensors as a function of exposure time were then measured, and the detection limit of the ME biosensor was determined to be 5 times 103 cfu/ml. View full abstract»

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  • Validation of HDOP Measure for Impact Detection in Sensor Network-Based Structural Health Monitoring

    Publication Year: 2009 , Page(s): 1098 - 1102
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (561 KB) |  | HTML iconHTML  

    This paper studies the validity of horizontal dilution of precision (HDOP) measure to evaluate sensor network geometries when localizing impacts in structural health monitoring (SHM). First, HDOP is defined similarly to navigation applications. Even though several low-complexity closed-form solutions have been proposed recently, HDOP measure has been theoretically justified only for iterative least-squares approach. The localization errors of popular impact localization methods are experimentally collected and compared with HDOP data for validation. The experimental setup is also described. It is shown that HDOP, in general, correlates with the positioning error and can be used to characterize geometry. View full abstract»

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  • A Small and Low-Cost 3-D Tactile Sensor for a Wearable Force Plate

    Publication Year: 2009 , Page(s): 1103 - 1110
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1396 KB) |  | HTML iconHTML  

    In this paper, a new 3-D tactile sensor is proposed for measuring triaxial ground reaction force (GRF) distribution. A pressure-sensitive electric conductive rubber (PSECR) and compact pectinate circuits were used to design the sensing cells of the sensor, making it possible to implement a low-cost and compact system without a complex 3-D structure. Moreover, to tailor the application for measuring human GRF, we adopted the use of elastic rubber as the contact interface of the sensor in order to realize a comfortable human-sensor interface. Calibration and test experiments were conducted to characterize the developed sensor, and a small triaxial force sensor (Tec Gihan, Japan) as well as a six-axial force sensor (Nitta Corporation, Japan) were used as verification measurement devices. Coupling effect tests were performed to calculate cross-sensitivity of the sensor. The experimental results of repeatability, nonlinearity, hysteresis, and dynamic tests indicate that the sensor is feasible for implementing 3-D tactile measurement. View full abstract»

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  • Using Nanometer Platinum Films as Temperature Sensors (Constraints From Experimental, Mathematical, and Finite-Element Analysis)

    Publication Year: 2009 , Page(s): 1111 - 1117
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB) |  | HTML iconHTML  

    It has been recognized that metallic films can be used for temperature sensing. It has been recently reported that the relationship between electrical resistance and temperature for thin platinum films (of nanometer size thicknesses) is linear provided that the temperature is below a certain level. However, when temperatures are above this level, the electrical resistance remains relatively constant. To get a better understanding of the properties of these nanometer-sized films, further characterization was performed. This characterization includes mathematical calculations and finite-element analysis to determine the relationships between the thermal properties and the electrical properties. Evaluation of these thin-film sensors shows that the sensitivity (i.e., change in resistance with respect to temperature) is approximately half of the bulk value and the measurement error due to Joule heating should not be an issue. View full abstract»

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  • A Limited Resources-Based Approach to Coding for Wireless Video Sensor Networks

    Publication Year: 2009 , Page(s): 1118 - 1124
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (726 KB) |  | HTML iconHTML  

    Coding for the wireless video sensor networks should be a different issue from the coding for video telephony applications. There are two special features observed in the video sensor networks, limited resources, and low fidelity. Due to these features, coding for this network application requires a new perspective. It is a direction for coding to be of simple structure and not for the entertainment purpose but sufficient for the basic sensing needs. Our coding method is accordingly developed as follows: motion compensation followed by a new idea of shape compensation to replace the conventional residue discrete cosine transform coding. More specifically, our binary images are coded by the motion vectors and the class of morphological filters to achieve a bit rate below 10 kp/s. The resources (bandwidth, power, and hardware) are thus altogether significantly saved. This limited resources approach is the first time particularly investigated for the wireless sensor networks. View full abstract»

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  • Distributed Temperature Sensor Interrogator Based on Polarization-Sensitive Reflectometry

    Publication Year: 2009 , Page(s): 1125 - 1129
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (811 KB) |  | HTML iconHTML  

    In this paper, a polarization-sensitive reflectometry technique has been investigated in order to serve as an interrogating device in distributed sensing applications. As the sensing fiber has a beat length of about a few centimeters, a high-resolution reflectometer was required. A coherent optical frequency-domain reflectometer (OFDR) was used from this perspective. The principle is based on the linear dependence of fiber beat length on temperature. The reported experimental results detail the calibration method and discuss the features of the interrogating device in terms of temperature threshold and spatial resolution. The proposed system, exploiting the Rayleigh backscatter signal, offers an interesting alternative to existing systems, mainly based on nonlinear effects. View full abstract»

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  • Thin Flexible Pressure Sensor Array Based on Carbon Black/Silicone Rubber Nanocomposite

    Publication Year: 2009 , Page(s): 1130 - 1135
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (902 KB) |  | HTML iconHTML  

    In this paper, the key technologies for the development of the thin flexible pressure sensor array based on carbon black/silicone rubber nanocomposite are reported. The piezoresistive mechanism of the nanocomposite is explained by analyzing the changes in effective conductive paths. The technical data of the sensor system are given. With the measurement range of 0-1 MPa, the maximum measurement deviation is less than 30 kPa. View full abstract»

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  • Analysis of Nano and Molecular Arrays of Negative Differential Resistance Devices for Sensing and Electronics

    Publication Year: 2009 , Page(s): 1136 - 1141
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (902 KB) |  | HTML iconHTML  

    We develop a mathematical procedure to simulate and analyze circuits of molecular devices presenting negative differential resistance. Our software implements deterministic and random methods to predict and explain programmability of configurable molecular arrays to perform logical, mathematical, and sensing tasks. A random method is developed to find all operation states a negative differential resistance circuit can yield. This information is valuable and would be difficult to obtain from classical circuit simulation. View full abstract»

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  • Lamb Wave Sensor for Viscous Fluids Characterization

    Publication Year: 2009 , Page(s): 1142 - 1147
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (888 KB) |  | HTML iconHTML  

    This paper is a study of a new sensor for fluid characterization. This sensor is composed of a stainless steel plate in contact with a viscous material. The aim is to characterize the material viscosity by using reflected Lamb waves at the boundary interface. In order to identify the effects on the Lamb reflected modes by the viscous material, a complete study of the propagation wave in the alone plate is first presented. The propagation modes of the loaded plate are then investigated. By monitoring the mechanical impedance, the viscosity of the material in contact is extracted. In order to validate the experimental setup, the mechanical impedance variation is measured for different water-glycerol mixtures. Results are in good agreement with those obtained by other techniques in the literature. View full abstract»

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  • Optical Salinity Sensor System Based on Fiber-Optic Array

    Publication Year: 2009 , Page(s): 1148 - 1153
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (718 KB) |  | HTML iconHTML  

    The refractive index of salt water changes corresponding to the variation of salinity. Based on a differential refractometer, the salinity can be measured due to beam deviation, and the influence of temperature on the measurement results is reduced effectively. Beam deviation caused by salinity change is detected by a fiber-optic array and recorded by a charge-coupled device. According to the Gauss distribution theory, the light-spot center can be determined by fitting a Gauss curve using each received light spot intensity and the position of each receiving fiber. With this method, measurement errors caused by light power fluctuation and ambient light disturbance can be avoided effectively. Variation in transmission power loss of each receiving fiber reduces the measurement accuracy of salinity. Therefore, a method of correction for each fiber transmission power loss in the array can effectively improve the salinity measurement accuracy. Experimental results indicate the feasibility of the developed system, and the measurement repeatability error is better than plusmn0.250/00 . View full abstract»

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  • X-Ray Image Detector Based on Light Guides and Scintillators

    Publication Year: 2009 , Page(s): 1154 - 1159
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (983 KB) |  | HTML iconHTML  

    This paper reports on a study concerning the design of an X-ray detector that is suitable to analyze a small area with high spatial resolution. The indirect method of X-ray detection is used, i.e., the X-rays are first converted into visible light, which is then detected. In this design, an array of CsI:Tl scintillators, encapsulated by aluminum walls, is coupled with an array of CMOS photodetectors. This structure, patented and described theoretically by the authors in previous works, can be obtained using the SU-8 negative photoresist as a sacrificial layer. The experimental work consisted in the deposition of a scintillator layer, and an aluminum layer on the active area of a commercially available digital imaging sensor, thus supporting the developed detector design. X-ray imaging tests were performed using the PHILIPS X'Pert equipment. Promising results were obtained, featuring high resolution and detail. View full abstract»

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  • Surface Type Classification With a Laser Range Finder

    Publication Year: 2009 , Page(s): 1160 - 1168
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (875 KB) |  | HTML iconHTML  

    This paper presents a system for surface classification using a laser range finder. It is shown that the return intensities and range errors provide sufficient information to distinguish a wide range of surfaces commonly found in a number of environments. A supervised learning scheme (using curves representing the return intensity and range error as a function of angle of incidence) is used to classify the surface type of planar patches. Extensive experimental evidence is presented to demonstrate the potential of the proposed technique. The surface type classification, which uses a typical laser range finder, is targeted for use with autonomous robotic systems in which significantly different interaction is required for each of the various materials present. Results from an on-site experiment demonstrate that the information from the laser range finder is sufficient to identify the different materials (via their surface properties) present in a scene where a bridge structure is being prepared for grit blasting. View full abstract»

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  • Scitopia.org [advertisement]

    Publication Year: 2009 , Page(s): 1169
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    Freely Available from IEEE

Aims & Scope

The IEEE Sensors Journal is a peer-reviewed, monthly online/print  journal devoted to sensors and sensing phenomena

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Meet Our Editors

Editor-in-Chief
Krikor Ozanyan
University of Manchester
Manchester, M13 9PL, U.K.