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Sensors, Volume 8, Issue 2 (February 2008), Pages 594-1350

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Displaying articles 1-46
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Open AccessArticle Techno-Economic Analysis of Solar Water Heating Systems inTurkey
Sensors 2008, 8(2), 1252-1277; https://doi.org/10.3390/s8021252
Received: 24 January 2008 / Accepted: 19 February 2008 / Published: 25 February 2008
Cited by 11 | PDF Full-text (1941 KB) | HTML Full-text | XML Full-text
Abstract
In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and
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In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type’s heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators. Full article
Open AccessArticle Range and Velocity Estimation of Moving Targets Using Multiple Stepped-frequency Pulse Trains
Sensors 2008, 8(2), 1343-1350; https://doi.org/10.3390/s8021343
Received: 2 February 2008 / Accepted: 20 February 2008 / Published: 22 February 2008
Cited by 25 | PDF Full-text (224 KB) | HTML Full-text | XML Full-text
Abstract
Range and velocity estimation of moving targets using conventional steppedfrequencypulse radar may suffer from the range-Doppler coupling and the phasewrapping. To overcome these problems, this paper presents a new radar waveform namedmultiple stepped-frequency pulse trains and proposes a new algorithm. It is shown
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Range and velocity estimation of moving targets using conventional steppedfrequencypulse radar may suffer from the range-Doppler coupling and the phasewrapping. To overcome these problems, this paper presents a new radar waveform namedmultiple stepped-frequency pulse trains and proposes a new algorithm. It is shown that byusing multiple stepped-frequency pulse trains and the robust phase unwrapping theorem(RPUT), both of the range-Doppler coupling and the phase wrapping can be robustlyresolved, and accordingly, the range and the velocity of a moving target can be accuratelyestimated. Full article
(This article belongs to the Special Issue Aerospace Sensor Systems)
Open AccessArticle The Successive Projection Algorithm (SPA), an Algorithm with a Spatial Constraint for the Automatic Search of Endmembers in Hyperspectral Data
Sensors 2008, 8(2), 1321-1342; https://doi.org/10.3390/s8021321
Received: 28 December 2007 / Accepted: 19 February 2008 / Published: 22 February 2008
Cited by 37 | PDF Full-text (2793 KB) | HTML Full-text | XML Full-text
Abstract
Spectral mixing is a problem inherent to remote sensing data and results in fewimage pixel spectra representing "pure" targets. Linear spectral mixture analysis isdesigned to address this problem and it assumes that the pixel-to-pixel variability in ascene results from varying proportions of spectral
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Spectral mixing is a problem inherent to remote sensing data and results in fewimage pixel spectra representing "pure" targets. Linear spectral mixture analysis isdesigned to address this problem and it assumes that the pixel-to-pixel variability in ascene results from varying proportions of spectral endmembers. In this paper we present adifferent endmember-search algorithm called the Successive Projection Algorithm (SPA).SPA builds on convex geometry and orthogonal projection common to other endmembersearch algorithms by including a constraint on the spatial adjacency of endmembercandidate pixels. Consequently it can reduce the susceptibility to outlier pixels andgenerates realistic endmembers.This is demonstrated using two case studies (AVIRISCuprite cube and Probe-1 imagery for Baffin Island) where image endmembers can bevalidated with ground truth data. The SPA algorithm extracts endmembers fromhyperspectral data without having to reduce the data dimensionality. It uses the spectralangle (alike IEA) and the spatial adjacency of pixels in the image to constrain the selectionof candidate pixels representing an endmember. We designed SPA based on theobservation that many targets have spatial continuity (e.g. bedrock lithologies) in imageryand thus a spatial constraint would be beneficial in the endmember search. An additionalproduct of the SPA is data describing the change of the simplex volume ratio between successive iterations during the endmember extraction. It illustrates the influence of a newendmember on the data structure, and provides information on the convergence of thealgorithm. It can provide a general guideline to constrain the total number of endmembersin a search. Full article
(This article belongs to the Special Issue Remote Sensing of Natural Resources and the Environment)
Open AccessArticle Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting
Sensors 2008, 8(2), 1308-1320; https://doi.org/10.3390/s8021308
Received: 15 February 2008 / Accepted: 21 February 2008 / Published: 22 February 2008
Cited by 15 | PDF Full-text (6644 KB) | HTML Full-text | XML Full-text
Abstract
For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS) technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection
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For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS) technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a preprocess, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels. Full article
(This article belongs to the Special Issue Modeling, Testing and Reliability Issues in MEMS Engineering)
Open AccessArticle Construction of a nrdA::luxCDABE Fusion and Its Use in Escherichia coli as a DNA Damage Biosensor
Sensors 2008, 8(2), 1297-1307; https://doi.org/10.3390/s8021297
Received: 31 January 2008 / Accepted: 21 February 2008 / Published: 22 February 2008
Cited by 16 | PDF Full-text (388 KB) | HTML Full-text | XML Full-text
Abstract
The promoter of nrdA gene which is related with DNA synthesis was used to construct a DNA damage sensitive biosensor. A recombinant bioluminescent E. coli strain, BBTNrdA, harboring a plasmid with the nrdA promoter fused to the luxCDABE operon, was successfully constructed. Its
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The promoter of nrdA gene which is related with DNA synthesis was used to construct a DNA damage sensitive biosensor. A recombinant bioluminescent E. coli strain, BBTNrdA, harboring a plasmid with the nrdA promoter fused to the luxCDABE operon, was successfully constructed. Its response to various chemicals including genotoxic chemicals substantiates it as a DNA damage biosensor. In characterization, three different classes of toxicants were used: DNA damaging chemicals, oxidative stress chemicals, and phenolics. BBTNrdA only responded strongly to DNA damaging chemicals, such as nalidixic acid (NDA), mitomycin C (MMC), 1-methyl-1-nitroso-N-methylguanidine (MNNG), and 4-nitroquinoline N-oxide (4-NQO). In contrast, there were no responses from the oxidative stress chemicals and phenolics, except from hydrogen peroxide (H2O2) which is known to cause DNA damage indirectly. Therefore, the results of the study demonstrate that BBTNrdA can be used as a DNA damage biosensor. Full article
Open AccessArticle Road Asphalt Pavements Analyzed by Airborne Thermal Remote Sensing: Preliminary Results of the Venice Highway
Sensors 2008, 8(2), 1278-1296; https://doi.org/10.3390/s8021278
Received: 5 February 2008 / Accepted: 21 February 2008 / Published: 22 February 2008
Cited by 26 | PDF Full-text (1159 KB) | HTML Full-text | XML Full-text
Abstract
This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the
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This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the roads’ asphalt pavements on Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery using a segmentation procedure. Next, since in asphalt pavements the surface defects are strictly related to the decrease of oily components that cause an increase of the abundance of surfacing limestone, the diagnostic absorption emissivity peak at 11.2μm of the limestone was used for retrieving from MIVIS emissivity data the areas exhibiting defects on asphalt pavements surface.The results showed that MIVIS emissivity allows establishing a threshold that points out those asphalt road sites on which a check for a maintenance intervention is required. Therefore, this technique can supply local government authorities an efficient, rapid and repeatable road mapping procedure providing the location of the asphalt pavements to be checked. Full article
(This article belongs to the Special Issue Sensors for Urban Environmental Monitoring)
Open AccessArticle Application of GeoWEPP for Determining Sediment Yield and Runoff in the Orcan Creek Watershed in Kahramanmaras, Turkey
Sensors 2008, 8(2), 1222-1236; https://doi.org/10.3390/s8021222
Received: 25 January 2008 / Accepted: 13 February 2008 / Published: 22 February 2008
Cited by 20 | PDF Full-text (2044 KB) | HTML Full-text | XML Full-text
Abstract
The geo-spatial interface of the WEPP model called GeoWEPP uses digital geo-referenced information integrated with the most common GIS tools to predict sedimentyield and runoff. The model determines where and when the sediment yield and runoffoccurs and locates possible deposition places. In this
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The geo-spatial interface of the WEPP model called GeoWEPP uses digital geo-referenced information integrated with the most common GIS tools to predict sedimentyield and runoff. The model determines where and when the sediment yield and runoffoccurs and locates possible deposition places. In this study, the sediment yield and runofffrom Orcan Creek watershed in Kahramanmaras region was estimated by using GeoWEPPmodel. To investigate the performance of the model, the sediment yield and runoff resultsfrom the GeoWEPP model were compared with the observed monthly data collected fromthe sample watershed. The average Root Mean Square Errors (RMSE) between observedand predicted average annual sediment yield and runoff were 2.96 and 8.43, respectively.The index of agreement was 0.98 and 0.99 for sediment yield and runoff, respectively,which indicated that the model predictions provided good results. Full article
Open AccessReview Imaging In Mice With Fluorescent Proteins: From Macro To Subcellular
Sensors 2008, 8(2), 1157-1173; https://doi.org/10.3390/s8021157
Received: 15 January 2008 / Accepted: 19 February 2008 / Published: 22 February 2008
Cited by 12 | PDF Full-text (4388 KB) | HTML Full-text | XML Full-text
Abstract
Whole-body imaging with fluorescent proteins has been shown to be a powerfultechnology with many applications in small animals. Brighter, red-shifted proteins can makewhole-body imaging even more sensitive due to reduced absorption by tissues and less scatter.For example, a new protein called Katushka has
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Whole-body imaging with fluorescent proteins has been shown to be a powerfultechnology with many applications in small animals. Brighter, red-shifted proteins can makewhole-body imaging even more sensitive due to reduced absorption by tissues and less scatter.For example, a new protein called Katushka has been isolated that is the brightest known proteinwith emission at wavelengths longer than 620 nm. This new protein offers potential for non-invasive whole-body macro imaging such as of tumor growth. For subcellular imaging, toobserve cytoplasmic and nuclear dynamics in the living mouse, cancer cells were labeled in thenucleus with green fluorescent protein and with red fluorescent protein in the cytoplasm. Thenuclear and cytoplasmic behavior of cancer cells in real time in blood vessels was imaged as theytrafficked by various means or adhered to the vessel surface in the abdominal skin flap. Duringextravasation, real-time dual-color imaging showed that cytoplasmic processes of the cancer cellsexited the vessels first, with nuclei following along the cytoplasmic projections. Both cytoplasmand nuclei underwent deformation during extravasation. Cancer cells trafficking in lymphaticvessels was also imaged. To noninvasively image cancer cell/stromal cell interaction in the tumormicroenvironment as well as drug response at the cellular level in live animals in real time, wedeveloped a new imageable three-color animal model. The model consists of GFP-expressingmice transplanted with the dual-color cancer cells. With the dual-color cancer cells and a highlysensitive small animal imaging system, subcellular dynamics can now be observed in live mice inreal time. Fluorescent proteins thus enable both macro and micro imaging technology and thereby provide the basis for the new field of in vivo cell biology. Full article
(This article belongs to the Special Issue Bioanalysis in Vivo/in Vitro)
Open AccessArticle Using ASTER Imagery in Land Use/cover Classification of Eastern Mediterranean Landscapes According to CORINE Land Cover Project
Sensors 2008, 8(2), 1237-1251; https://doi.org/10.3390/s8021287
Received: 7 February 2008 / Accepted: 19 February 2008 / Published: 21 February 2008
Cited by 37 | PDF Full-text (4057 KB) | HTML Full-text | XML Full-text
Abstract
The satellite imagery has been effectively utilized for classifying land covertypes and detecting land cover conditions. The Advanced Spaceborne Thermal Emissionand Reflection Radiometer (ASTER) sensor imagery has been widely used in classificationprocess of land cover. However, atmospheric corrections have to be made by
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The satellite imagery has been effectively utilized for classifying land covertypes and detecting land cover conditions. The Advanced Spaceborne Thermal Emissionand Reflection Radiometer (ASTER) sensor imagery has been widely used in classificationprocess of land cover. However, atmospheric corrections have to be made by preprocessingsatellite sensor imagery since the electromagnetic radiation signals received by the satellitesensors can be scattered and absorbed by the atmospheric gases and aerosols. In this study,an ASTER sensor imagery, which was converted into top-of-atmosphere reflectance(TOA), was used to classify the land use/cover types, according to COoRdination ofINformation on the Environment (CORINE) land cover nomenclature, for an arearepresenting the heterogonous characteristics of eastern Mediterranean regions inKahramanmaras, Turkey. The results indicated that using the surface reflectance data ofASTER sensor imagery can provide accurate (i.e. overall accuracy and kappa values of83.2% and 0.79, respectively) and low-cost cover mapping as a part of inventory forCORINE Land Cover Project. Full article
Open AccessArticle An Auto-Recognizing System for Dice Games Using a Modified Unsupervised Grey Clustering Algorithm
Sensors 2008, 8(2), 1212-1221; https://doi.org/10.3390/s8021212
Received: 17 November 2007 / Accepted: 14 February 2007 / Published: 21 February 2008
Cited by 17 | PDF Full-text (437 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a novel identification method based on a machine vision system is proposed to recognize the score of dice. The system employs image processing techniques, and the modified unsupervised grey clustering algorithm (MUGCA) to estimate the location of each die and
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In this paper, a novel identification method based on a machine vision system is proposed to recognize the score of dice. The system employs image processing techniques, and the modified unsupervised grey clustering algorithm (MUGCA) to estimate the location of each die and identify the spot number accurately and effectively. The proposed algorithms are substituted for manual recognition. From the experimental results, it is found that this system is excellent due to its good capabilities which include flexibility, high speed, and high accuracy. Full article
(This article belongs to the Special Issue Intelligent Sensors)
Open AccessArticle Dependence of Impedance of Embedded Single Cells on Cellular Behaviour
Sensors 2008, 8(2), 1198-1211; https://doi.org/10.3390/s8021198
Received: 31 January 2008 / Accepted: 20 February 2007 / Published: 21 February 2008
Cited by 10 | PDF Full-text (1431 KB) | HTML Full-text | XML Full-text
Abstract
Non-invasive single cell analyses are increasingly required for the medicaldiagnostics of test substances or the development of drugs and therapies on the single celllevel. For the non-invasive characterisation of cells, impedance spectroscopy whichprovides the frequency dependent electrical properties has been used. Recently,microfludic systems
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Non-invasive single cell analyses are increasingly required for the medicaldiagnostics of test substances or the development of drugs and therapies on the single celllevel. For the non-invasive characterisation of cells, impedance spectroscopy whichprovides the frequency dependent electrical properties has been used. Recently,microfludic systems have been investigated to manipulate the single cells and tocharacterise the electrical properties of embedded cells. In this article, the impedance ofpartially embedded single cells dependent on the cellular behaviour was investigated byusing the microcapillary. An analytical equation was derived to relate the impedance ofembedded cells with respect to the morphological and physiological change ofextracellular interface. The capillary system with impedance measurement showed afeasibility to monitor the impedance change of embedded single cells caused bymorphological and physiological change of cell during the addition of DMSO. By fittingthe derived equation to the measured impedance of cell embedded at different negativepressure levels, it was able to extrapolate the equivalent gap and gap conductivity betweenthe cell and capillary wall representing the cellular behaviour. Full article
Open AccessArticle Temporal Stability of Soil Moisture and Radar Backscatter Observed by the Advanced Synthetic Aperture Radar (ASAR)
Sensors 2008, 8(2), 1174-1197; https://doi.org/10.3390/s80201174
Received: 11 January 2008 / Accepted: 19 February 2008 / Published: 21 February 2008
Cited by 22 | PDF Full-text (1333 KB) | HTML Full-text | XML Full-text
Abstract
The high spatio-temporal variability of soil moisture is the result of atmosphericforcing and redistribution processes related to terrain, soil, and vegetation characteristics.Despite this high variability, many field studies have shown that in the temporal domainsoil moisture measured at specific locations is correlated to
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The high spatio-temporal variability of soil moisture is the result of atmosphericforcing and redistribution processes related to terrain, soil, and vegetation characteristics.Despite this high variability, many field studies have shown that in the temporal domainsoil moisture measured at specific locations is correlated to the mean soil moisture contentover an area. Since the measurements taken by Synthetic Aperture Radar (SAR)instruments are very sensitive to soil moisture it is hypothesized that the temporally stablesoil moisture patterns are reflected in the radar backscatter measurements. To verify this hypothesis 73 Wide Swath (WS) images have been acquired by the ENVISAT AdvancedSynthetic Aperture Radar (ASAR) over the REMEDHUS soil moisture network located inthe Duero basin, Spain. It is found that a time-invariant linear relationship is well suited forrelating local scale (pixel) and regional scale (50 km) backscatter. The observed linearmodel coefficients can be estimated by considering the scattering properties of the terrainand vegetation and the soil moisture scaling properties. For both linear model coefficients,the relative error between observed and modelled values is less than 5 % and thecoefficient of determination (R2) is 86 %. The results are of relevance for interpreting anddownscaling coarse resolution soil moisture data retrieved from active (METOP ASCAT)and passive (SMOS, AMSR-E) instruments. Full article
(This article belongs to the Special Issue Synthetic Aperture Radar (SAR))
Open AccessArticle Comparison of Remote Sensing Image Processing Techniques to Identify Tornado Damage Areas from Landsat TM Data
Sensors 2008, 8(2), 1128-1156; https://doi.org/10.3390/s8021128
Received: 31 December 2007 / Accepted: 19 February 2008 / Published: 21 February 2008
Cited by 30 | PDF Full-text (14585 KB) | HTML Full-text | XML Full-text
Abstract
Remote sensing techniques have been shown effective for large-scale damagesurveys after a hazardous event in both near real-time or post-event analyses. The paperaims to compare accuracy of common imaging processing techniques to detect tornadodamage tracks from Landsat TM data. We employed the direct
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Remote sensing techniques have been shown effective for large-scale damagesurveys after a hazardous event in both near real-time or post-event analyses. The paperaims to compare accuracy of common imaging processing techniques to detect tornadodamage tracks from Landsat TM data. We employed the direct change detection approachusing two sets of images acquired before and after the tornado event to produce a principalcomponent composite images and a set of image difference bands. Techniques in thecomparison include supervised classification, unsupervised classification, and object-oriented classification approach with a nearest neighbor classifier. Accuracy assessment isbased on Kappa coefficient calculated from error matrices which cross tabulate correctlyidentified cells on the TM image and commission and omission errors in the result. Overall,the Object-oriented Approach exhibits the highest degree of accuracy in tornado damagedetection. PCA and Image Differencing methods show comparable outcomes. Whileselected PCs can improve detection accuracy 5 to 10%, the Object-oriented Approachperforms significantly better with 15-20% higher accuracy than the other two techniques. Full article
Open AccessArticle Integrated Electrochemical Analysis System with Microfluidic and Sensing Functions
Sensors 2008, 8(2), 1111-1127; https://doi.org/10.3390/s8021111
Received: 17 January 2008 / Accepted: 18 February 2008 / Published: 21 February 2008
Cited by 18 | PDF Full-text (1342 KB) | HTML Full-text | XML Full-text
Abstract
An integrated device that carries out the timely transport of solutions andconducts electroanalysis was constructed. The transport of solutions was based oncapillary action in overall hydrophilic flow channels and control by valves that operateon the basis of electrowetting. Electrochemical sensors including glucose, lactate,glutamic
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An integrated device that carries out the timely transport of solutions andconducts electroanalysis was constructed. The transport of solutions was based oncapillary action in overall hydrophilic flow channels and control by valves that operateon the basis of electrowetting. Electrochemical sensors including glucose, lactate,glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), pH,ammonia, urea, and creatinine were integrated. An air gap structure was used for theammonia, urea, and creatinine sensors to realize a rapid response. To enhance thetransport of ammonia that existed or was produced by the enzymatic reactions, the pHof the solution was elevated by mixing it with a NaOH solution using a valve based onelectrowetting. The sensors for GOT and GPT used a freeze-dried substrate matrix torealize rapid mixing. The sample solution was transported to required sensing sites atdesired times. The integrated sensors showed distinct responses when a sample solutionreached the respective sensing sites. Linear relationships were observed between theoutput signals and the concentration or the logarithm of the concentration of theanalytes. An interferent, L-ascorbic acid, could be eliminated electrochemically in thesample injection port. Full article
Open AccessReview QoS Challenges and Opportunities in Wireless Sensor/Actuator Networks
Sensors 2008, 8(2), 1099-1110; https://doi.org/10.3390/s8021099
Received: 29 December 2007 / Accepted: 18 February 2008 / Published: 21 February 2008
Cited by 145 | PDF Full-text (209 KB) | HTML Full-text | XML Full-text
Abstract
A wireless sensor/actuator network (WSAN) is a group of sensors and actuators that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Actuators react to this information by performing appropriate actions. WSANs thus enable cyber
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A wireless sensor/actuator network (WSAN) is a group of sensors and actuators that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Actuators react to this information by performing appropriate actions. WSANs thus enable cyber systems to monitor and manipulate the behavior of the physical world. WSANs are growing at a tremendous pace, just like the exploding evolution of Internet. Supporting quality of service (QoS) will be of critical importance for pervasive WSANs that serve as the network infrastructure of diverse applications. To spark new research and development interests in this field, this paper examines and discusses the requirements, critical challenges, and open research issues on QoS management in WSANs. A brief overview of recent progress is given. Full article
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