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Sensors, Volume 13, Issue 4 (April 2013) , Pages 3998-5405

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Open AccessCorrection Correction: Lee, Y. et al. Geosensor Data Representation Using Layered Slope Grids. Sensors 2012, 12, 17074-17093
Sensors 2013, 13(4), 5404-5405; https://doi.org/10.3390/s130405404
Received: 4 March 2013 / Revised: 16 April 2013 / Accepted: 16 April 2013 / Published: 22 April 2013
Viewed by 2295 | PDF Full-text (184 KB) | HTML Full-text | XML Full-text
Abstract
There are four mistakes at the table derived from the (c) surface slope of Figure 4 in [1]. The direction numbers are derived according to (a) slope directions. The overall direction number should be changed from 6 to 4. The distinct direction number [...] Read more.
There are four mistakes at the table derived from the (c) surface slope of Figure 4 in [1]. The direction numbers are derived according to (a) slope directions. The overall direction number should be changed from 6 to 4. The distinct direction number between the 1st and 2nd subcells should be changed from 0 to 8. The distinct direction number between the 2nd and 3rd subcells should be changed from 8 to 4. The distinct direction number between the 3rd and 4th subcells should be changed from 4 to 6. The authors would like to apologize for any inconvenience this may have caused to the readers of this journal. [...] Full article
(This article belongs to the Section Chemical Sensors)
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Open AccessCorrection Correction: Zarzo, M. et al. Long-Term Monitoring of Fresco Paintings in the Cathedral of Valencia (Spain) through Humidity and Temperature Sensors in Various Locations for Preventive Conservation. Sensors 2011, 11, 8685-8710
Sensors 2013, 13(4), 5403; https://doi.org/10.3390/s130405403
Received: 14 March 2013 / Revised: 25 March 2013 / Accepted: 25 March 2013 / Published: 22 April 2013
Viewed by 2223 | PDF Full-text (114 KB) | HTML Full-text | XML Full-text
Abstract
A typo has been found in our paper [1]. It is stated on page 8698 that the range of acceptable temperature for the conservation of frescoes is 6–25 °C while in the case of RH, this range is 45%–60%, according to the Italian [...] Read more.
A typo has been found in our paper [1]. It is stated on page 8698 that the range of acceptable temperature for the conservation of frescoes is 6–25 °C while in the case of RH, this range is 45%–60%, according to the Italian Standard UNI 10829 (1999). These recommended ranges of temperature (6–25 °C) and RH (45%–60%) correspond to the Standard DM 10/2001 [2], not to UNI 10829. The authors would like to apologize for any inconvenience this may have caused to the readers of this journal. [...] Full article
(This article belongs to the Section Chemical Sensors)
Open AccessArticle Computational Burden Resulting from Image Recognition of High Resolution Radar Sensors
Sensors 2013, 13(4), 5381-5402; https://doi.org/10.3390/s130405381
Received: 21 February 2013 / Revised: 12 April 2013 / Accepted: 12 April 2013 / Published: 22 April 2013
Cited by 6 | Viewed by 3146 | PDF Full-text (1323 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a methodology for high resolution radar image generation and automatic target recognition emphasizing the computational cost involved in the process. In order to obtain focused inverse synthetic aperture radar (ISAR) images certain signal processing algorithms must be applied to the [...] Read more.
This paper presents a methodology for high resolution radar image generation and automatic target recognition emphasizing the computational cost involved in the process. In order to obtain focused inverse synthetic aperture radar (ISAR) images certain signal processing algorithms must be applied to the information sensed by the radar. From actual data collected by radar the stages and algorithms needed to obtain ISAR images are revised, including high resolution range profile generation, motion compensation and ISAR formation. Target recognition is achieved by comparing the generated set of actual ISAR images with a database of ISAR images generated by electromagnetic software. High resolution radar image generation and target recognition processes are burdensome and time consuming, so to determine the most suitable implementation platform the analysis of the computational complexity is of great interest. To this end and since target identification must be completed in real time, computational burden of both processes the generation and comparison with a database is explained separately. Conclusions are drawn about implementation platforms and calculation efficiency in order to reduce time consumption in a possible future implementation. Full article
Open AccessArticle Validation of Noninvasive MOEMS-Assisted Measurement System Based on CCD Sensor for Radial Pulse Analysis
Sensors 2013, 13(4), 5368-5380; https://doi.org/10.3390/s130405368
Received: 30 January 2013 / Revised: 22 March 2013 / Accepted: 25 March 2013 / Published: 22 April 2013
Cited by 10 | Viewed by 4049 | PDF Full-text (1020 KB) | HTML Full-text | XML Full-text
Abstract
Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner’s subjective technical skills and judgment. Consequently, it lacks reliability and [...] Read more.
Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner’s subjective technical skills and judgment. Consequently, it lacks reliability and consistency, which limits practical applications in clinical medicine. Thus, quantifiable characterization of the wrist pulse diagnosis method is a prerequisite for its further development and widespread use. This paper reports application of a noninvasive CCD sensor-based hybrid measurement system for radial pulse signal analysis. First, artery wall deformations caused by the blood flow are calibrated with a laser triangulation displacement sensor, following by the measurement of the deformations with projection moiré method. Different input pressures and fluids of various viscosities are used in the assembled artificial blood flow system in order to test the performance of laser triangulation technique with detection sensitivity enhancement through microfabricated retroreflective optical element placed on a synthetic vascular graft. Subsequently, the applicability of double-exposure whole-field projection moiré technique for registration of blood flow pulses is considered: a computational model and representative example are provided, followed by in vitro experiment performed on a vascular graft with artificial skin atop, which validates the suitability of the technique for characterization of skin surface deformations caused by the radial pulsation. Full article
(This article belongs to the Special Issue Laser Sensing and Imaging)
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Open AccessArticle Cramer-Rao Bounds and Coherence Performance Analysis for Next Generation Radar with Pulse Trains
Sensors 2013, 13(4), 5347-5367; https://doi.org/10.3390/s130405347
Received: 1 March 2013 / Revised: 28 March 2013 / Accepted: 16 April 2013 / Published: 22 April 2013
Cited by 19 | Viewed by 3372 | PDF Full-text (405 KB) | HTML Full-text | XML Full-text
Abstract
We study the Cramer-Rao bounds of parameter estimation and coherence performance for the next generation radar (NGR). In order to enhance the performance of NGR, the signal model of NGR with master-slave architecture based on a single pulse is extended to the case [...] Read more.
We study the Cramer-Rao bounds of parameter estimation and coherence performance for the next generation radar (NGR). In order to enhance the performance of NGR, the signal model of NGR with master-slave architecture based on a single pulse is extended to the case of pulse trains, in which multiple pulses are emitted from all sensors and then integrated spatially and temporally in a unique master sensor. For the MIMO mode of NGR where orthogonal waveforms are emitted, we derive the closed-form Cramer-Rao bound (CRB) for the estimates of generalized coherence parameters (GCPs), including the time delay differences, total phase differences and Doppler frequencies with respect to different sensors. For the coherent mode of NGR where the coherent waveforms are emitted after pre-compensation using the estimates of GCPs, we develop a performance bound of signal-to-noise ratio (SNR) gain for NGR based on the aforementioned CRBs, taking all the estimation errors into consideration. It is shown that greatly improved estimation accuracy and coherence performance can be obtained with pulse trains employed in NGR. Numerical examples demonstrate the validity of the theoretical results. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle Open-Source Colorimeter
Sensors 2013, 13(4), 5338-5346; https://doi.org/10.3390/s130405338
Received: 31 January 2013 / Revised: 11 April 2013 / Accepted: 16 April 2013 / Published: 19 April 2013
Cited by 65 | Viewed by 10259 | PDF Full-text (266 KB) | HTML Full-text | XML Full-text
Abstract
The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A [...] Read more.
The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories. Full article
(This article belongs to the Section Chemical Sensors)
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Open AccessArticle Classification of Sporting Activities Using Smartphone Accelerometers
Sensors 2013, 13(4), 5317-5337; https://doi.org/10.3390/s130405317
Received: 26 February 2013 / Revised: 8 April 2013 / Accepted: 11 April 2013 / Published: 19 April 2013
Cited by 65 | Viewed by 4925 | PDF Full-text (1015 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we present a framework that allows for the automatic identification of sporting activities using commonly available smartphones. We extract discriminative informational features from smartphone accelerometers using the Discrete Wavelet Transform (DWT). Despite the poor quality of their accelerometers, smartphones were [...] Read more.
In this paper we present a framework that allows for the automatic identification of sporting activities using commonly available smartphones. We extract discriminative informational features from smartphone accelerometers using the Discrete Wavelet Transform (DWT). Despite the poor quality of their accelerometers, smartphones were used as capture devices due to their prevalence in today’s society. Successful classification on this basis potentially makes the technology accessible to both elite and non-elite athletes. Extracted features are used to train different categories of classifiers. No one classifier family has a reportable direct advantage in activity classification problems to date; thus we examine classifiers from each of the most widely used classifier families. We investigate three classification approaches; a commonly used SVM-based approach, an optimized classification model and a fusion of classifiers. We also investigate the effect of changing several of the DWT input parameters, including mother wavelets, window lengths and DWT decomposition levels. During the course of this work we created a challenging sports activity analysis dataset, comprised of soccer and field-hockey activities. The average maximum F-measure accuracy of 87% was achieved using a fusion of classifiers, which was 6% better than a single classifier model and 23% better than a standard SVM approach. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle A PARALIND Decomposition-Based Coherent Two-Dimensional Direction of Arrival Estimation Algorithm for Acoustic Vector-Sensor Arrays
Sensors 2013, 13(4), 5302-5316; https://doi.org/10.3390/s130405302
Received: 20 February 2013 / Revised: 28 March 2013 / Accepted: 4 April 2013 / Published: 19 April 2013
Cited by 12 | Viewed by 2658 | PDF Full-text (315 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we combine the acoustic vector-sensor array parameter estimation problem with the parallel profiles with linear dependencies (PARALIND) model, which was originally applied to biology and chemistry. Exploiting the PARALIND decomposition approach, we propose a blind coherent two-dimensional direction of arrival [...] Read more.
In this paper, we combine the acoustic vector-sensor array parameter estimation problem with the parallel profiles with linear dependencies (PARALIND) model, which was originally applied to biology and chemistry. Exploiting the PARALIND decomposition approach, we propose a blind coherent two-dimensional direction of arrival (2D-DOA) estimation algorithm for arbitrarily spaced acoustic vector-sensor arrays subject to unknown locations. The proposed algorithm works well to achieve automatically paired azimuth and elevation angles for coherent and incoherent angle estimation of acoustic vector-sensor arrays, as well as the paired correlated matrix of the sources. Our algorithm, in contrast with conventional coherent angle estimation algorithms such as the forward backward spatial smoothing (FBSS) estimation of signal parameters via rotational invariance technique (ESPRIT) algorithm, not only has much better angle estimation performance, even for closely-spaced sources, but is also available for arbitrary arrays. Simulation results verify the effectiveness of our algorithm. Full article
(This article belongs to the Special Issue Last Trends in Acoustic Sensing)
Open AccessArticle Amperometric Immunosensor for Carbofuran Detection Based on MWCNTs/GS-PEI-Au and AuNPs-Antibody Conjugate
Sensors 2013, 13(4), 5286-5301; https://doi.org/10.3390/s130405286
Received: 28 February 2013 / Revised: 11 April 2013 / Accepted: 12 April 2013 / Published: 19 April 2013
Cited by 18 | Viewed by 3605 | PDF Full-text (965 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface [...] Read more.
In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab) and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD), ultraviolet and visible absorption spectroscopy (UV-vis) and scanning electron microscopy (SEM), respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3). The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication. Full article
(This article belongs to the Section Biosensors)
Open AccessArticle Development of Robust and Standardized Cantilever Sensors Based on Biotin/Neutravidin Coupling for Antibody Detection
Sensors 2013, 13(4), 5273-5285; https://doi.org/10.3390/s130405273
Received: 14 March 2013 / Revised: 10 April 2013 / Accepted: 15 April 2013 / Published: 19 April 2013
Cited by 8 | Viewed by 3018 | PDF Full-text (956 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A cantilever-based protein biosensor has been developed providing a customizable multilayer platform for the detection of antibodies. It consists of a biotin-terminated PEG layer pre-functionalized on the gold-coated cantilever surface, onto which NeutrAvidin is adsorbed through biotin/NeutrAvidin specific binding. NeutrAvidin is used as [...] Read more.
A cantilever-based protein biosensor has been developed providing a customizable multilayer platform for the detection of antibodies. It consists of a biotin-terminated PEG layer pre-functionalized on the gold-coated cantilever surface, onto which NeutrAvidin is adsorbed through biotin/NeutrAvidin specific binding. NeutrAvidin is used as a bridge layer between the biotin-coated surface and the biotinylated biomolecules, such as biotinylated bovine serum albumin (biotinylated BSA), forming a multilayer sensor for direct antibody capture. The cantilever biosensor has been successfully applied to the detection of mouse anti-BSA (m-IgG) and sheep anti-BSA(s-IgG) antibodies. As expected, the average differential surface stress signals of about 5.7 ± 0.8 ´ 10−3 N/m are very similar for BSA/m-IgG and BSA/s-IgG binding, i.e., they are independent of the origin of the antibody. A statistic evaluation of 112 response curves confirms that the multilayer protein cantilever biosensor shows high reproducibility. As a control test, a biotinylated maltose binding protein was used for detecting specificity of IgG, the result shows a signal of bBSA layer in response to antibody is 5.8 ´ 10−3 N/m compared to bMBP. The pre-functionalized biotin/PEG cantilever surface is found to show a long shelf-life of at least 40 days and retains its responsivity of above 70% of the signal when stored in PBS buffer at 4 °C. The protein cantilever biosensor represents a rapid, label-free, sensitive and reliable detection technique for a real-time protein assay. Full article
(This article belongs to the Section Biosensors)
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Open AccessArticle Optimal Periodic Cooperative Spectrum Sensing Based on Weight Fusion in Cognitive Radio Networks
Sensors 2013, 13(4), 5251-5272; https://doi.org/10.3390/s130405251
Received: 29 January 2013 / Revised: 5 April 2013 / Accepted: 11 April 2013 / Published: 19 April 2013
Cited by 28 | Viewed by 3132 | PDF Full-text (351 KB) | HTML Full-text | XML Full-text
Abstract
The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic [...] Read more.
The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic cooperative spectrum sensing model based on weight fusion is proposed in this paper. Moreover, the sensing period, the sensing time and the searching time are optimized, respectively. Firstly the sensing period is optimized to improve the spectrum utilization and reduce the interference, then the joint optimization algorithm of the local sensing time and the number of cooperative users, is proposed to obtain the optimal sensing time for improving the throughput of the cognitive radio user (CRU) during each period, and finally the water-filling principle is applied to optimize the searching time in order to make the CRU find an idle channel within the shortest time. The simulation results show that compared with the previous algorithms, the optimal sensing period can improve the spectrum utilization of the CRU and decrease the interference to the PU significantly, the optimal sensing time can make the CRU achieve the largest throughput, and the optimal searching time can make the CRU find an idle channel with the least time. Full article
(This article belongs to the Section Sensor Networks)
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Open AccessArticle Identifying the Key Factors Affecting Warning Message Dissemination in VANET Real Urban Scenarios
Sensors 2013, 13(4), 5220-5250; https://doi.org/10.3390/s130405220
Received: 21 February 2013 / Revised: 8 April 2013 / Accepted: 12 April 2013 / Published: 19 April 2013
Cited by 11 | Viewed by 3465 | PDF Full-text (627 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, new architectures and technologies have been proposed for Vehicular Ad Hoc networks (VANETs). Due to the cost and complexity of deploying such networks, most of these proposals rely on simulation. However, we find that most of the experiments made to [...] Read more.
In recent years, new architectures and technologies have been proposed for Vehicular Ad Hoc networks (VANETs). Due to the cost and complexity of deploying such networks, most of these proposals rely on simulation. However, we find that most of the experiments made to validate these proposals tend to overlook the most important and representative factors. Moreover, the scenarios simulated tend to be very simplistic (highways or Manhattan-based layouts), which could seriously affect the validity of the obtained results. In this paper, we present a statistical analysis based on the 2k factorial methodology to determine the most representative factors affecting traffic safety applications under real roadmaps. Our purpose is to determine which are the key factors affecting Warning Message Dissemination in order to concentrate research tests on such parameters, thus avoiding unnecessary simulations and reducing the amount of simulation time required. Simulation results show that the key factors affecting warning messages delivery are the density of vehicles and the roadmap used. Based on this statistical analysis, we consider that VANET researchers must evaluate the benefits of their proposals using different vehicle densities and city scenarios, to obtain a broad perspective on the effectiveness of their solution. Finally, since city maps can be quite heterogeneous, we propose a roadmap profile classification to further reduce the number of cities evaluated. Full article
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Open AccessArticle An Ink-Jet Printed Eddy Current Position Sensor
Sensors 2013, 13(4), 5205-5219; https://doi.org/10.3390/s130405205
Received: 17 February 2013 / Revised: 26 March 2013 / Accepted: 26 March 2013 / Published: 18 April 2013
Cited by 11 | Viewed by 3327 | PDF Full-text (826 KB) | HTML Full-text | XML Full-text
Abstract
An eddy current sensor with an ink-jet printed flexible inductor has been designed and fabricated. The inductor has been designed by means of software developed in-house. It has been fabricated by ink-jet printing with silver ink on a flexible substrate. The inductor is [...] Read more.
An eddy current sensor with an ink-jet printed flexible inductor has been designed and fabricated. The inductor has been designed by means of software developed in-house. It has been fabricated by ink-jet printing with silver ink on a flexible substrate. The inductor is a part of the oscillator circuit whose oscillating frequency is measured by a microcontroller. The sensor characteristics have been analyzed for two types of application. The first considered application is the displacement of a large conductive target in a direction perpendicular to the inductor plane. The second considered application is the displacement of a small steel ball parallel to the inductor plane. Inductance and oscillating frequency have been measured in order to completely characterize the sensor. The obtained results validate the use of the sensor for both considered applications, and are in good agreement with the simulations. The advantages of this type of sensor are low cost, the possibility for the inductor to match any curved surface and flexibility and precision of the inductor design. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle Experimental Investigation on Adaptive Robust Controller Designs Applied to Constrained Manipulators
Sensors 2013, 13(4), 5181-5204; https://doi.org/10.3390/s130405181
Received: 5 April 2013 / Revised: 16 April 2013 / Accepted: 16 April 2013 / Published: 18 April 2013
Cited by 1 | Viewed by 2674 | PDF Full-text (3187 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, two interlaced studies are presented. The first is directed to the design and construction of a dynamic 3D force/moment sensor. The device is applied to provide a feedback signal of forces and moments exerted by the robotic end-effector. This development [...] Read more.
In this paper, two interlaced studies are presented. The first is directed to the design and construction of a dynamic 3D force/moment sensor. The device is applied to provide a feedback signal of forces and moments exerted by the robotic end-effector. This development has become an alternative solution to the existing multi-axis load cell based on static force and moment sensors. The second one shows an experimental investigation on the performance of four different adaptive nonlinear H control methods applied to a constrained manipulator subject to uncertainties in the model and external disturbances. Coordinated position and force control is evaluated. Adaptive procedures are based on neural networks and fuzzy systems applied in two different modeling strategies. The first modeling strategy requires a well-known nominal model for the robot, so that the intelligent systems are applied only to estimate the effects of uncertainties, unmodeled dynamics and external disturbances. The second strategy considers that the robot model is completely unknown and, therefore, intelligent systems are used to estimate these dynamics. A comparative study is conducted based on experimental implementations performed with an actual planar manipulator and with the dynamic force sensor developed for this purpose. Full article
(This article belongs to the Special Issue Piezoelectric Sensors and Actuators)
Open AccessArticle Performance Evaluation of a Modular Detector Unit for X-Ray Computed Tomography
Sensors 2013, 13(4), 5167-5180; https://doi.org/10.3390/s130405167
Received: 6 February 2013 / Revised: 15 April 2013 / Accepted: 16 April 2013 / Published: 18 April 2013
Cited by 1 | Viewed by 3044 | PDF Full-text (808 KB) | HTML Full-text | XML Full-text
Abstract
A research prototype CT scanner is currently under development in our lab. One of the key components in this project is the CT detector. This paper describes the design and performance evaluation of the modular CT detector unit for our proposed scanner. It [...] Read more.
A research prototype CT scanner is currently under development in our lab. One of the key components in this project is the CT detector. This paper describes the design and performance evaluation of the modular CT detector unit for our proposed scanner. It consists of a Photodiode Array Assembly which captures irradiating X-ray photons and converts the energy into electrical current, and a mini Data Acquisition System which performs current integration and converts the analog signal into digital samples. The detector unit can be easily tiled together to form a CT detector. Experiments were conducted to characterize the detector performance both at the single unit level and system level. The noise level, linearity and uniformity of the proposed detector unit were reported and initial imaging studies were also presented which demonstrated the potential application of the proposed detector unit in actual CT scanners. Full article
(This article belongs to the Special Issue Medical & Biological Imaging)
Open AccessReview Targeting agr- and agr-Like Quorum Sensing Systems for Development of Common Therapeutics to Treat Multiple Gram-Positive Bacterial Infections
Sensors 2013, 13(4), 5130-5166; https://doi.org/10.3390/s130405130
Received: 27 February 2013 / Revised: 6 April 2013 / Accepted: 12 April 2013 / Published: 18 April 2013
Cited by 50 | Viewed by 4722 | PDF Full-text (465 KB) | HTML Full-text | XML Full-text
Abstract
Invasive infection by the Gram-positive pathogen Staphylococcus aureus is controlled by a four gene operon, agr that encodes a quorum sensing system for the regulation of virulence. While agr has been well studied in S. aureus, the contribution of agr homologues and [...] Read more.
Invasive infection by the Gram-positive pathogen Staphylococcus aureus is controlled by a four gene operon, agr that encodes a quorum sensing system for the regulation of virulence. While agr has been well studied in S. aureus, the contribution of agr homologues and analogues in other Gram-positive pathogens is just beginning to be understood. Intriguingly, other significant human pathogens, including Clostridium perfringens, Listeria monocytogenes, and Enterococcus faecalis contain agr or analogues linked to virulence. Moreover, other significant human Gram-positive pathogens use peptide based quorum sensing systems to establish or maintain infection. The potential for commonality in aspects of these signaling systems across different species raises the prospect of identifying therapeutics that could target multiple pathogens. Here, we review the status of research into these agr homologues, analogues, and other peptide based quorum sensing systems in Gram-positive pathogens as well as the potential for identifying common pathways and signaling mechanisms for therapeutic discovery. Full article
(This article belongs to the Section Biosensors)
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Open AccessArticle Caffeine as a Potential Quorum Sensing Inhibitor
Sensors 2013, 13(4), 5117-5129; https://doi.org/10.3390/s130405117
Received: 25 February 2013 / Revised: 10 April 2013 / Accepted: 16 April 2013 / Published: 18 April 2013
Cited by 45 | Viewed by 5497 | PDF Full-text (393 KB) | HTML Full-text | XML Full-text
Abstract
Quorum sensing enables bacteria to control the gene expression in response to the cell density. It regulates a variety of bacterial physiological functions such as biofilm formation, bioluminescence, virulence factors and swarming which has been shown contribute to bacterial pathogenesis. The use of [...] Read more.
Quorum sensing enables bacteria to control the gene expression in response to the cell density. It regulates a variety of bacterial physiological functions such as biofilm formation, bioluminescence, virulence factors and swarming which has been shown contribute to bacterial pathogenesis. The use of quorum sensing inhibitor would be of particular interest in treating bacterial pathogenicity and infections. In this work, we have tested caffeine as quorum sensing inhibitor by using Chromobacterium violaceum CV026 as a biosensor. We verified that caffeine did not degrade the N-acyl homoserine lactones tested. In this work, it is shown that caffeine could inhibit N-acyl homoserine lactone production and swarming of a human opportunistic pathogen, namely Pseudomonas aeruginosa PA01. To the best of our knowledge, this is the first documentation providing evidence on the presence of anti-quorum sensing activity in caffeine. Our work will allow caffeine to be explored as anti-infective drugs. Full article
(This article belongs to the Section Biosensors)
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Open AccessArticle Performance Improvement of the One-Dot Lateral Flow Immunoassay for Aflatoxin B1 by Using a Smartphone-Based Reading System
Sensors 2013, 13(4), 5109-5116; https://doi.org/10.3390/s130405109
Received: 6 February 2013 / Revised: 25 March 2013 / Accepted: 10 April 2013 / Published: 18 April 2013
Cited by 36 | Viewed by 4294 | PDF Full-text (543 KB) | HTML Full-text | XML Full-text
Abstract
This study was conducted to develop a simple, rapid, and accurate lateral flow immunoassay (LFIA) detection method for point-of-care diagnosis. The one-dot LFIA for aflatoxin B1 (AFB1) was based on the modified competitive binding format using competition between AFB1 and colloidal gold-AFB1-BSA conjugate [...] Read more.
This study was conducted to develop a simple, rapid, and accurate lateral flow immunoassay (LFIA) detection method for point-of-care diagnosis. The one-dot LFIA for aflatoxin B1 (AFB1) was based on the modified competitive binding format using competition between AFB1 and colloidal gold-AFB1-BSA conjugate for antibody binding sites in the test zone. A Smartphone-based reading system consisting of a Samsung Galaxy S2 Smartphone, a LFIA reader, and a Smartphone application for the image acquisition and data analysis. The detection limit of one-dot LFIA for AFB1 is 5 μg/kg. This method provided semi-quantitative analysis of AFB1 samples in the range of 5 to 1,000 μg/kg. Using combination of the one-dot LFIA and the Smartphone-based reading system, it is possible to conduct a more fast and accurate point-of-care diagnosis. Full article
Open AccessArticle A Low-Cost, Computer-Interfaced Drawing Pad for fMRI Studies of Dysgraphia and Dyslexia
Sensors 2013, 13(4), 5099-5108; https://doi.org/10.3390/s130405099
Received: 20 March 2013 / Revised: 10 April 2013 / Accepted: 11 April 2013 / Published: 17 April 2013
Cited by 7 | Viewed by 8168 | PDF Full-text (877 KB) | HTML Full-text | XML Full-text
Abstract
We have developed a pen and writing tablet for use by subjects during fMRI scanning. The pen consists of two jacketed, multi-mode optical fibers routed to the tip of a hollowed-out ball-point pen. The pen has been further modified by addition of a [...] Read more.
We have developed a pen and writing tablet for use by subjects during fMRI scanning. The pen consists of two jacketed, multi-mode optical fibers routed to the tip of a hollowed-out ball-point pen. The pen has been further modified by addition of a plastic plate to maintain a perpendicular pen-tablet orientation. The tablet is simply a non-metallic frame holding a paper print of continuously varying color gradients. The optical fibers are routed out of the MRI bore to a light-tight box in an adjacent control room. Within the box, light from a high intensity LED is coupled into one of the fibers, while the other fiber abuts a color sensor. Light from the LED exits the pen tip, illuminating a small spot on the tablet, and the resulting reflected light is routed to the color sensor. Given a lookup table of position for each color on the tablet, the coordinates of the pen on the tablet may be displayed and digitized in real-time. While simple and inexpensive, the system achieves sufficient resolution to grade writing tasks testing dysgraphic and dyslexic phenomena. Full article
(This article belongs to the Special Issue Medical & Biological Imaging)
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Open AccessReview Progress in Infrared Photodetectors Since 2000
Sensors 2013, 13(4), 5054-5098; https://doi.org/10.3390/s130405054
Received: 23 January 2013 / Revised: 3 April 2013 / Accepted: 9 April 2013 / Published: 16 April 2013
Cited by 91 | Viewed by 4421 | PDF Full-text (701 KB) | HTML Full-text | XML Full-text
Abstract
The first decade of the 21st-century has seen a rapid development in infrared photodetector technology. At the end of the last millennium there were two dominant IR systems, InSb- and HgCdTe-based detectors, which were well developed and available in commercial systems. While these [...] Read more.
The first decade of the 21st-century has seen a rapid development in infrared photodetector technology. At the end of the last millennium there were two dominant IR systems, InSb- and HgCdTe-based detectors, which were well developed and available in commercial systems. While these two systems saw improvements over the last twelve years, their change has not nearly been as marked as that of the quantum-based detectors (i.e., QWIPs, QDIPs, DWELL-IPs, and SLS-based photodetectors). In this paper, we review the progress made in all of these systems over the last decade plus, compare the relative merits of the systems as they stand now, and discuss where some of the leading research groups in these fields are going to take these technologies in the years to come. Full article
(This article belongs to the Special Issue Photodetectors)
Open AccessArticle 3D Image Acquisition System Based on Shape from Focus Technique
Sensors 2013, 13(4), 5040-5053; https://doi.org/10.3390/s130405040
Received: 28 February 2013 / Revised: 10 April 2013 / Accepted: 11 April 2013 / Published: 15 April 2013
Cited by 13 | Viewed by 5126 | PDF Full-text (2403 KB) | HTML Full-text | XML Full-text
Abstract
This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. [...] Read more.
This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. Our system is based on the Shape from Focus technique initially used in the microscopic domain. We propose to adapt this technique to the macroscopic domain and we detail the system as well as the image processing used to perform such technique. The Shape from Focus technique is a monocular and passive 3D acquisition method that resolves the occlusion problem affecting the multi-cameras systems. Indeed, this problem occurs frequently in natural complex scenes like agronomic scenes. The depth information is obtained by acting on optical parameters and mainly the depth of field. A focus measure is applied on a 2D image stack previously acquired by the system. When this focus measure is performed, we can create the depth map of the scene. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Optimization of Hydrogen Peroxide Detection for a Methyl Mercaptan Biosensor
Sensors 2013, 13(4), 5028-5039; https://doi.org/10.3390/s130405028
Received: 11 March 2013 / Revised: 3 April 2013 / Accepted: 7 April 2013 / Published: 15 April 2013
Cited by 11 | Viewed by 3411 | PDF Full-text (282 KB) | HTML Full-text | XML Full-text
Abstract
Several kinds of modified carbon screen printed electrodes (CSPEs) for amperometric detection of hydrogen peroxide (H2O2) are presented in order to propose a methyl mercaptan (MM) biosensor. Unmodified, carbon nanotubes (CNTs), cobalt phthalocyanine (CoPC), Prussian blue (PB), and Os-wired [...] Read more.
Several kinds of modified carbon screen printed electrodes (CSPEs) for amperometric detection of hydrogen peroxide (H2O2) are presented in order to propose a methyl mercaptan (MM) biosensor. Unmodified, carbon nanotubes (CNTs), cobalt phthalocyanine (CoPC), Prussian blue (PB), and Os-wired HRP modified CSPE sensors were fabricated and tested to detect H2O2, applying a potential of +0.6 V, +0.6 V, +0.4 V, −0.2 V and −0.1 V (versus Ag/AgCl), respectively. The limits of detection of these electrodes for H2O2 were 3.1 μM, 1.3 μM, 71 nM, 1.3 μM, 13.7 nM, respectively. The results demonstrated that the Os-wired HRP modified CSPEs gives the lowest limit of detection (LOD) for H2O2 at a working potential as low as −0.1 V. Os-wired HRP is the optimum choice for establishment of a MM biosensor and gives a detection limit of 0.5 μM. Full article
(This article belongs to the Special Issue Enzymatic Biosensors)
Open AccessArticle Application of the Electronic Nose Technique to Differentiation between Model Mixtures with COPD Markers
Sensors 2013, 13(4), 5008-5027; https://doi.org/10.3390/s130405008
Received: 11 January 2013 / Revised: 27 March 2013 / Accepted: 27 March 2013 / Published: 15 April 2013
Cited by 14 | Viewed by 3011 | PDF Full-text (1451 KB) | HTML Full-text | XML Full-text
Abstract
The paper presents the potential of an electronic nose technique in the field of fast diagnostics of patients suspected of Chronic Obstructive Pulmonary Disease (COPD). The investigations were performed using a simple electronic nose prototype equipped with a set of six semiconductor sensors [...] Read more.
The paper presents the potential of an electronic nose technique in the field of fast diagnostics of patients suspected of Chronic Obstructive Pulmonary Disease (COPD). The investigations were performed using a simple electronic nose prototype equipped with a set of six semiconductor sensors manufactured by FIGARO Co. They were aimed at verification of a possibility of differentiation between model reference mixtures with potential COPD markers (N,N-dimethylformamide and N,N-dimethylacetamide). These mixtures contained volatile organic compounds (VOCs) such as acetone, isoprene, carbon disulphide, propan-2-ol, formamide, benzene, toluene, acetonitrile, acetic acid, dimethyl ether, dimethyl sulphide, acrolein, furan, propanol and pyridine, recognized as the components of exhaled air. The model reference mixtures were prepared at three concentration levels—10 ppb, 25 ppb, 50 ppb v/v—of each component, except for the COPD markers. Concentration of the COPD markers in the mixtures was from 0 ppb to 100 ppb v/v. Interpretation of the obtained data employed principal component analysis (PCA). The investigations revealed the usefulness of the electronic device only in the case when the concentration of the COPD markers was twice as high as the concentration of the remaining components of the mixture and for a limited number of basic mixture components. Full article
(This article belongs to the Section Chemical Sensors)
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Open AccessArticle Study of the Electrocatalytic Activity of Cerium Oxide and Gold-Studded Cerium Oxide Nanoparticles Using a Sonogel-Carbon Material as Supporting Electrode: Electroanalytical Study in Apple Juice for Babies
Sensors 2013, 13(4), 4979-5007; https://doi.org/10.3390/s130404979
Received: 28 February 2013 / Revised: 8 April 2013 / Accepted: 9 April 2013 / Published: 12 April 2013
Cited by 12 | Viewed by 4629 | PDF Full-text (2586 KB) | HTML Full-text | XML Full-text
Abstract
The present work reports a study of the electrocatalytic activity of CeO2 nanoparticles and gold sononanoparticles (AuSNPs)/CeO2 nanocomposite, deposited on the surface of a Sonogel-Carbon (SNGC) matrix used as supporting electrode and the application of the sensing devices built with them [...] Read more.
The present work reports a study of the electrocatalytic activity of CeO2 nanoparticles and gold sononanoparticles (AuSNPs)/CeO2 nanocomposite, deposited on the surface of a Sonogel-Carbon (SNGC) matrix used as supporting electrode and the application of the sensing devices built with them to the determination of ascorbic acid (AA) used as a benchmark analyte. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrocatalytic behavior of CeO2- and AuSNPs/CeO2-modified SNGC electrodes, utilizing different concentrations of CeO2 nanoparticles and different AuSNPs:CeO2 w/w ratios. The best detection and quantification limits, obtained for CeO2 (10.0 mg·mL1)- and AuSNPs/CeO2 (3.25% w/w)-modified SNGC electrodes, were 1.59 × 10−6 and 5.32 × 10−6 M, and 2.93 × 10−6 and 9.77 × 10−6 M, respectively, with reproducibility values of 5.78% and 6.24%, respectively, for a linear concentration range from 1.5 µM to 4.0 mM of AA. The electrochemical devices were tested for the determination of AA in commercial apple juice for babies. The results were compared with those obtained by applying high performance liquid chromatography (HPLC) as a reference method. Recovery errors below 5% were obtained in most cases, with standard deviations lower than 3% for all the modified SNGC electrodes. Bare, CeO2- and AuSNPs/CeO2-modified SNGC electrodes were structurally characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). AuSNPs and AuSNPs/CeO2 nanocomposite were characterized by UV–vis spectroscopy and X-ray diffraction (XRD), and information about their size distribution and shape was obtained by transmission electron microscopy (TEM). The advantages of employing CeO2 nanoparticles and AuSNPs/CeO2 nanocomposite in SNGC supporting material are also described. This research suggests that the modified electrode can be a very promising voltammetric sensor for the determination of electroactive species of interest in real samples. Full article
(This article belongs to the Special Issue Novel Tools in Electrochemical Sensing)
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Open AccessReview Compressive Sensing Image Sensors-Hardware Implementation
Sensors 2013, 13(4), 4961-4978; https://doi.org/10.3390/s130404961
Received: 28 January 2013 / Revised: 27 March 2013 / Accepted: 4 April 2013 / Published: 12 April 2013
Cited by 18 | Viewed by 3411 | PDF Full-text (553 KB) | HTML Full-text | XML Full-text
Abstract
The compressive sensing (CS) paradigm uses simultaneous sensing and compression to provide an efficient image acquisition technique. The main advantages of the CS method include high resolution imaging using low resolution sensor arrays and faster image acquisition. Since the imaging philosophy in CS [...] Read more.
The compressive sensing (CS) paradigm uses simultaneous sensing and compression to provide an efficient image acquisition technique. The main advantages of the CS method include high resolution imaging using low resolution sensor arrays and faster image acquisition. Since the imaging philosophy in CS imagers is different from conventional imaging systems, new physical structures have been developed for cameras that use the CS technique. In this paper, a review of different hardware implementations of CS encoding in optical and electrical domains is presented. Considering the recent advances in CMOS (complementary metal–oxide–semiconductor) technologies and the feasibility of performing on-chip signal processing, important practical issues in the implementation of CS in CMOS sensors are emphasized. In addition, the CS coding for video capture is discussed. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Analysis and Description of HOLTIN Service Provision for AECG monitoring in Complex Indoor Environments
Sensors 2013, 13(4), 4947-4960; https://doi.org/10.3390/s130404947
Received: 11 March 2013 / Revised: 9 April 2013 / Accepted: 10 April 2013 / Published: 12 April 2013
Cited by 29 | Viewed by 2732 | PDF Full-text (2421 KB) | HTML Full-text | XML Full-text
Abstract
In this work, a novel ambulatory ECG monitoring device developed in-house called HOLTIN is analyzed when operating in complex indoor scenarios. The HOLTIN system is described, from the technological platform level to its functional model. In addition, by using in-house 3D ray launching [...] Read more.
In this work, a novel ambulatory ECG monitoring device developed in-house called HOLTIN is analyzed when operating in complex indoor scenarios. The HOLTIN system is described, from the technological platform level to its functional model. In addition, by using in-house 3D ray launching simulation code, the wireless channel behavior, which enables ubiquitous operation, is performed. The effect of human body presence is taken into account by a novel simplified model embedded within the 3D Ray Launching code. Simulation as well as measurement results are presented, showing good agreement. These results may aid in the adequate deployment of this novel device to automate conventional medical processes, increasing the coverage radius and optimizing energy consumption. Full article
Open AccessArticle Energy-Efficient Algorithm for Broadcasting in Ad Hoc Wireless Sensor Networks
Sensors 2013, 13(4), 4922-4946; https://doi.org/10.3390/s130404922
Received: 15 January 2013 / Revised: 21 March 2013 / Accepted: 22 March 2013 / Published: 12 April 2013
Cited by 21 | Viewed by 3360 | PDF Full-text (412 KB) | HTML Full-text | XML Full-text
Abstract
Broadcasting is a common and basic operation used to support various network protocols in wireless networks. To achieve energy-efficient broadcasting is especially important for ad hoc wireless sensor networks because sensors are generally powered by batteries with limited lifetimes. Energy consumption for broadcast [...] Read more.
Broadcasting is a common and basic operation used to support various network protocols in wireless networks. To achieve energy-efficient broadcasting is especially important for ad hoc wireless sensor networks because sensors are generally powered by batteries with limited lifetimes. Energy consumption for broadcast operations can be reduced by minimizing the number of relay nodes based on the observation that data transmission processes consume more energy than data reception processes in the sensor nodes, and how to improve the network lifetime is always an interesting issue in sensor network research. The minimum-energy broadcast problem is then equivalent to the problem of finding the minimum Connected Dominating Set (CDS) for a connected graph that is proved NP-complete. In this paper, we introduce an Efficient Minimum CDS algorithm (EMCDS) with help of a proposed ordered sequence list. EMCDS does not concern itself with node energy and broadcast operations might fail if relay nodes are out of energy. Next we have proposed a Minimum Energy-consumption Broadcast Scheme (MEBS) with a modified version of EMCDS, and aimed at providing an efficient scheduling scheme with maximized network lifetime. The simulation results show that the proposed EMCDS algorithm can find smaller CDS compared with related works, and the MEBS can help to increase the network lifetime by efficiently balancing energy among nodes in the networks. Full article
(This article belongs to the Special Issue Ubiquitous Sensing)
Open AccessArticle In-Situ Waviness Characterization of Metal Plates by a Lateral Shearing Interferometric Profilometer
Sensors 2013, 13(4), 4906-4921; https://doi.org/10.3390/s130404906
Received: 27 February 2013 / Revised: 14 March 2013 / Accepted: 27 March 2013 / Published: 12 April 2013
Cited by 5 | Viewed by 2709 | PDF Full-text (2668 KB) | HTML Full-text | XML Full-text
Abstract
Characterizing waviness in sheet metal is a key process for quality control in many industries, such as automotive and home appliance manufacturing. However, there is still no known technique able to work in an automated in-floor inspection system. The literature describes many techniques [...] Read more.
Characterizing waviness in sheet metal is a key process for quality control in many industries, such as automotive and home appliance manufacturing. However, there is still no known technique able to work in an automated in-floor inspection system. The literature describes many techniques developed in the last three decades, but most of them are either slow, only able to work in laboratory conditions, need very short (unsafe) working distances, or are only able to estimate certain waviness parameters. In this article we propose the use of a lateral shearing interferometric profilometer, which is able to obtain a 19 mm profile in a single acquisition, with sub-micron precision, in an uncontrolled environment, and from a working distance greater than 90 mm. This system allows direct measurement of all needed waviness parameters even with objects in movement. We describe a series of experiments over several samples of steel plates to validate the sensor and the processing method, and the results are in close agreement with those obtained with a contact stylus device. The sensor is an ideal candidate for on-line or in-machine fast automatic waviness assessment, reducing delays and costs in many metalworking processes. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Estimation of Distribution Algorithm for Resource Allocation in Green Cooperative Cognitive Radio Sensor Networks
Sensors 2013, 13(4), 4884-4905; https://doi.org/10.3390/s130404884
Received: 22 February 2013 / Revised: 18 March 2013 / Accepted: 20 March 2013 / Published: 12 April 2013
Cited by 13 | Viewed by 3048 | PDF Full-text (229 KB) | HTML Full-text | XML Full-text
Abstract
Due to the rapid increase in the usage and demand of wireless sensor networks (WSN), the limited frequency spectrum available for WSN applications will be extremely crowded in the near future. More sensor devices also mean more recharging/replacement of batteries, which will cause [...] Read more.
Due to the rapid increase in the usage and demand of wireless sensor networks (WSN), the limited frequency spectrum available for WSN applications will be extremely crowded in the near future. More sensor devices also mean more recharging/replacement of batteries, which will cause significant impact on the global carbon footprint. In this paper, we propose a relay-assisted cognitive radio sensor network (CRSN) that allocates communication resources in an environmentally friendly manner. We use shared band amplify and forward relaying for cooperative communication in the proposed CRSN. We present a multi-objective optimization architecture for resource allocation in a green cooperative cognitive radio sensor network (GC-CRSN). The proposed multi-objective framework jointly performs relay assignment and power allocation in GC-CRSN, while optimizing two conflicting objectives. The first objective is to maximize the total throughput, and the second objective is to minimize the total transmission power of CRSN. The proposed relay assignment and power allocation problem is a non-convex mixed-integer non-linear optimization problem (NC-MINLP), which is generally non-deterministic polynomial-time (NP)-hard. We introduce a hybrid heuristic algorithm for this problem. The hybrid heuristic includes an estimation-of-distribution algorithm (EDA) for performing power allocation and iterative greedy schemes for constraint satisfaction and relay assignment. We analyze the throughput and power consumption tradeoff in GC-CRSN. A detailed analysis of the performance of the proposed algorithm is presented with the simulation results. Full article
(This article belongs to the Section Sensor Networks)
Open AccessCommunication Near Infrared Spectral Linearisation in Quantifying Soluble Solids Content of Intact Carambola
Sensors 2013, 13(4), 4876-4883; https://doi.org/10.3390/s130404876
Received: 20 January 2013 / Revised: 23 March 2013 / Accepted: 28 March 2013 / Published: 12 April 2013
Cited by 4 | Viewed by 2628 | PDF Full-text (194 KB) | HTML Full-text | XML Full-text
Abstract
This study presents a novel application of near infrared (NIR) spectral linearisation for measuring the soluble solids content (SSC) of carambola fruits. NIR spectra were measured using reflectance and interactance methods. In this study, only the interactance measurement technique successfully generated a reliable [...] Read more.
This study presents a novel application of near infrared (NIR) spectral linearisation for measuring the soluble solids content (SSC) of carambola fruits. NIR spectra were measured using reflectance and interactance methods. In this study, only the interactance measurement technique successfully generated a reliable measurement result with a coefficient of determination of (R2) = 0.724 and a root mean square error of prediction for (RMSEP) = 0.461° Brix. The results from this technique produced a highly accurate and stable prediction model compared with multiple linear regression techniques. Full article
(This article belongs to the Section Physical Sensors)
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