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Sensors Journal, IEEE

Issue 2 • Date Apr 2002

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Displaying Results 1 - 8 of 8
  • Multilayer sensing and aggregation approach to environmental perception with one multifunctional sensor

    Page(s): 62 - 72
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (354 KB) |  | HTML iconHTML  

    This paper presents a novel approach to perception of a specified environment for intelligent system or robotics applications in which high-level information must be extracted from multi-sensors data. A CdS and Fe3O4 material based multifunction sensor has been developed to measure temperature, humidity and brightness. The sensor focuses on the processing of the multifunctional information in a multilayer framework, which is more attractive in terms of system simplicity, performance, and compact structure. Further along, quantity creditability tactics (QCT), one multisensing data fusion method, is approached, with which quantities are sequentially aggregated to generate a general perception about the sensed environment. Different from the popular fusion strategies, the proposed algorithm also works in a step-by-step framework, and proves to be more practical and more effective when there are more variables for calculation View full abstract»

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  • Multisensor fusion and integration: approaches, applications, and future research directions

    Page(s): 107 - 119
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (458 KB) |  | HTML iconHTML  

    Multisensor fusion and integration is a rapidly evolving research area and requires interdisciplinary knowledge in control theory, signal processing, artificial intelligence, probability and statistics, etc. The advantages gained through the use of redundant, complementary, or more timely information in a system can provide more reliable and accurate information. This paper provides an overview of current sensor technologies and describes the paradigm of multisensor fusion and integration as well as fusion techniques at different fusion levels. Applications of multisensor fusion in robotics, biomedical system, equipment monitoring, remote sensing, and transportation system are also discussed. Finally, future research directions of multisensor fusion technology including microsensors, smart sensors, and adaptive fusion techniques are presented View full abstract»

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  • A wireless, passive carbon nanotube-based gas sensor

    Page(s): 82 - 88
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB) |  | HTML iconHTML  

    A gas sensor, comprised of a gas-responsive multiwall carbon nanotube (MWNT)-silicon dioxide (SiO2) composite layer deposited on a planar inductor-capacitor resonant circuit is presented here for the monitoring of carbon dioxide (CO2), oxygen (O 2), and ammonia (NH3). The absorption of different gases in the MWNT-SiO2 layer changes the permittivity and conductivity of the material and consequently alters the resonant frequency of the sensor. By tracking the frequency spectrum of the sensor with a loop antenna, humidity, temperature, as well as CO2 , O2 and NH3 concentrations can be determined, enabling applications such as remotely monitoring conditions inside opaque, sealed containers. Experimental results show the sensor response to CO2 and O2 is both linear and reversible. Both irreversible and reversible responses are observed in response to NH3, indicating both physisorption and chemisorption of NH3 by the carbon nanotubes. A sensor array, comprised of an uncoated, SiO2 coated, and MWNT-SiO2 coated sensor, enables CO2 measurement to be automatically calibrated for operation in a variable humidity and temperature environment View full abstract»

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  • Hydrogen catalytic oxidation reaction on Pd-doped porous silicon

    Page(s): 89 - 95
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (250 KB) |  | HTML iconHTML  

    The efficiency of Pd-doped porous silicon (PS) as a catalytic material for hydrogen sensing is studied. Pd is deposited by an electroless process on the internal surface of porous silicon. The catalytic behavior of Pd-doped PS samples is estimated and the parameters that influence the kinetics of the chemical reaction are evaluated. The catalytic activity is examined through the kinetics of the chemical reaction, which occurs in low hydrogen content mixtures with air (up to 1% v/v in air), far below the mixture flammability limit. It was found that the catalytic activity of Pd-doped porous silicon at 160°C is significantly higher than that of a planar surface covered with Pd. The dependence of the catalytic activity on processing conditions was also evaluated. These results open important new possibilities for applications in gas sensors View full abstract»

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  • Thermal treatment stabilization processes in SnO2 thin films catalyzed with Au and Pt

    Page(s): 102 - 106
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (243 KB)  

    We examined the thermal treatment stabilization processes in SnO 2-based thin films for gas-sensing applications in order to understand their influence on structural properties and possible relations with functional behavior of the sensors. The films of SnO2 were deposited by magnetron sputtering, following the rules of the rheothaxial growth and thermal oxidation (RGTO) technique and annealed in humid synthetic air at 600°C. Afterward, a thin overlayer of gold or platinum was deposited on the oxidized films. The samples were characterized soon after catalyzer deposition and after one-hour aging process at 400°C, in order to evaluate stabilization process influence as a function of catalyzer. X-ray photoelectron spectroscopy (XPS) and scanning tunnelling microscopy (STM) demonstrated that a short aging affects the microstructure of gold-catalyzed samples, while it does not influence platinum catalyzed ones. The results of the microstructural characterization were confirmed by electrical measurements of gas-sensitivity: the short-aging influences the stability of gas-sensing parameters only in gold-catalyzed samples View full abstract»

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  • A 128×128 CMOS image sensor with analog memory for synchronous image capture

    Page(s): 120 - 127
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (306 KB) |  | HTML iconHTML  

    A 128×128 CMOS imager that permits synchronous capture is presented. The sensor combines the best of CMOS imagers (low-power, random readout, nondestructive readout, single supply voltage...) and synchronous capture [available in high-end charge coupled device (CCD) imagers]. The key point in obtaining such characteristics is the separation of the photosensor and the storage element. Although some sensors with these characteristics have been reported, in this sensor, the storage capability has been brought a step further, having storage times of the order of tens of seconds, and being able to use the array itself as a random access memory (RAM). This could avoid the use of external RAM, making the system simpler, more compact, and of low-power consumption View full abstract»

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  • Comparison of three humidity sensors for a pulmonary function diagnosis microsystem

    Page(s): 96 - 101
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    Three capacitive humidity sensors developed for a portable clinical application are presented and compared. The first structures consist of interdigitated electrodes covered by a polyimide sensitive layer. The second structures have the same geometry but include a benzocyclobutene sensitive layer and a heating. resistor. The third structure has been developed with a new geometry, with the electrodes being stacked. Humidity measurement results are presented, in particular sensor response time in absorption that must be very small (less than 500 ms). The influence of the heating on the response time is described. In conclusion, the three sensors are compared and the most suitable structure for our application is indicated. Although polyimide has been widely used for realization of capacitive humidity sensors, we demonstrate here that it is not the best sensitive material for our application View full abstract»

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  • State of the art in sensor technologies for sewer inspection

    Page(s): 73 - 81
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (263 KB)  

    This paper reviews the state of the art in sensors and automated inspection devices for enhanced sewer inspection. Efficiency, safety, environmental, and legislative concerns have made inspection and assessment of communal sewers a central issue to water and sewerage companies. Nowadays, the standard sewer inspection system is based on a wheeled platform on which a closed circuit television (CCTV) camera is mounted. One of the disadvantages of camera inspection systems is that they can only detect a small proportion of all possible damage in a sewer. The inspection outcome of such systems relies not only on the quality of the acquired images, but also on the off-line. recognition and classification conducted by human operators. In consequence, CCTV-based platforms are frequently not effective. Infrared, microwave, optical, and ultrasonic-based sensors have been proposed to complement the existing CCTV-based approach and to improve inspection results. New inspection devices employing multiple sensors and being capable of carrying out remote sewer inspection tasks are under research View full abstract»

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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.