Sensors

119 KiB

Open AccessArticle

An Improved Particle Filter for Target Tracking in Sensor Systems

by Xue Wang, Sheng Wang and Jun-Jie Ma

Sensors 2007, 7(1), 144-156; https://doi.org/10.3390/s7010144 - 29 Jan 2007

Cited by 75 | Viewed by 13376

Sensor systems are not always equipped with the ability to track targets. Sudden maneuvers of a target can have a great impact on the sensor system, which will increase the miss rate and rate of false target detection. The use of the generic [...] Read more.

Sensor systems are not always equipped with the ability to track targets. Sudden maneuvers of a target can have a great impact on the sensor system, which will increase the miss rate and rate of false target detection. The use of the generic particle filter (PF) algorithm is well known for target tracking, but it can not overcome the degeneracy of particles and cumulation of estimation errors. In this paper, we propose an improved PF algorithm called PF-RBF. This algorithm uses the radial-basis function network (RBFN) in the sampling step for dynamically constructing the process model from observations and updating the value of each particle. With the RBFN sampling step, PF-RBF can give an accurate proposal distribution and maintain the convergence of a sensor system. Simulation results verify that PF-RBF performs better than the Unscented Kalman Filter (UKF), PF and Unscented Particle Filter (UPF) in both robustness and accuracy whether the observation model used for the sensor system is linear or nonlinear. Moreover, the intrinsic property of PF-RBF determines that, when the particle number exceeds a certain amount, the execution time of PF-RBF is less than UPF. This makes PF-RBF a better candidate for the sensor systems which need many particles for target tracking. Full article

(This article belongs to the Special Issue Intelligent Sensors)

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237 KiB

Open AccessArticle

Classification of Mixtures of Odorants from Livestock Buildings by a Sensor Array (an Electronic Tongue)

by Nawaf Abu-Khalaf and Jens Jørgen Lønsmann Iversen

Sensors 2007, 7(1), 129-143; https://doi.org/10.3390/s7010129 - 29 Jan 2007

Cited by 10 | Viewed by 7550

Abstract

An electronic tongue comprising different numbers of electrodes was able to classify test mixtures of key odorants characteristic of bioscrubbers of livestock buildings (n-butyrate, iso-valerate, phenolate, p-cresolate, skatole and ammonium). The classification of model solutions indicates that the electronic tongue has a promising [...] Read more.

An electronic tongue comprising different numbers of electrodes was able to classify test mixtures of key odorants characteristic of bioscrubbers of livestock buildings (n-butyrate, iso-valerate, phenolate, p-cresolate, skatole and ammonium). The classification of model solutions indicates that the electronic tongue has a promising potential as an on- line sensor for characterization of odorants in livestock buildings. Back propagation artificial neural network was used for classification. The average classification rate was above 80% in all cases. A limited, but sufficient number of electrodes were selected by average classification rate and relative entropy. The sufficient number of electrodes decreased standard deviation and relative standard deviation compared to the full electrode array. Full article

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233 KiB

Open AccessArticle

Calibration of a Sensor Array (an Electronic Tongue) for Identification and Quantification of Odorants from Livestock Buildings

by Nawaf Abu-Khalaf and Jens Jørgen Lønsmann Iversen

Sensors 2007, 7(1), 103-128; https://doi.org/10.3390/s7010103 - 29 Jan 2007

Cited by 12 | Viewed by 8432

Abstract

This contribution serves a dual purpose. The first purpose was to investigate the possibility of using a sensor array (an electronic tongue) for on-line identification and quantification of key odorants representing a variety of chemical groups at two different acidities, pH 6 and [...] Read more.

This contribution serves a dual purpose. The first purpose was to investigate the possibility of using a sensor array (an electronic tongue) for on-line identification and quantification of key odorants representing a variety of chemical groups at two different acidities, pH 6 and 8. The second purpose was to simplify the electronic tongue by decreasing the number of electrodes from 14, which was the number of electrodes in the prototype. Different electrodes were used for identification and quantification of different key odorants. A total of eight electrodes were sufficient for identification and quantification in micromolar concentrations of the key odorants n-butyrate, ammonium and phenolate in test mixtures also containing iso-valerate, skatole and p-cresolate. The limited number of electrodes decreased the standard deviation and the relative standard deviation of triplicate measurements in comparison with the array comprising 14 electrodes. The electronic tongue was calibrated using 4 different test mixtures, each comprising 50 different combinations of key odorants in triplicates, a total of 600 measurements. Back propagation artificial neural network, partial least square and principal component analysis were used in the data analysis. The results indicate that the electronic tongue has a promising potential as an on- line sensor for odorants absorbed in the bioscrubber used in livestock buildings. Full article

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78 KiB

Open AccessReview

A Survey on Optimal Signal Processing Techniques Applied to Improve the Performance of Mechanical Sensors in Automotive Applications

by Wilmar Hernandez

Sensors 2007, 7(1), 84-102; https://doi.org/10.3390/s7010084 - 27 Jan 2007

Cited by 25 | Viewed by 9323

Abstract

In this paper a survey on recent applications of optimal signal processing techniques to improve the performance of mechanical sensors is made. Here, a comparison between classical filters and optimal filters for automotive sensors is made, and the current state of the art [...] Read more.

In this paper a survey on recent applications of optimal signal processing techniques to improve the performance of mechanical sensors is made. Here, a comparison between classical filters and optimal filters for automotive sensors is made, and the current state of the art of the application of robust and optimal control and signal processing techniques to the design of the intelligent (or smart) sensors that today’s cars need is presented through several experimental results that show that the fusion of intelligent sensors and optimal signal processing techniques is the clear way to go. However, the switch between the traditional methods of designing automotive sensors and the new ones cannot be done overnight because there are some open research issues that have to be solved. This paper draws attention to one of the open research issues and tries to arouse researcher’s interest in the fusion of intelligent sensors and optimal signal processing techniques. Full article

166 KiB

Open AccessArticle

E.M.I Effects of Cathodic Protection on Electromagnetic Flowmeters

by Serdar Gundogdu and Ozge Sahin

Sensors 2007, 7(1), 75-83; https://doi.org/10.3390/s7010075 - 26 Jan 2007

Cited by 5 | Viewed by 14437

Abstract

Electromagnetic flowmeters are used to measure the speed of water flow in water distribution systems. Corrosion problem in metal pipelines can be solved by cathodic protection methods. This paper presents a research on corruptive effects of the cathodic protection system on electromagnetic flowmeter [...] Read more.

Electromagnetic flowmeters are used to measure the speed of water flow in water distribution systems. Corrosion problem in metal pipelines can be solved by cathodic protection methods. This paper presents a research on corruptive effects of the cathodic protection system on electromagnetic flowmeter depending on its measuring principle. Experimental measurements are realized on the water distribution pipelines of the Izmir Municipality, Department of Water and Drainage Administration (IZSU) in Turkey and measurement results are given. Experimental results proved that the values measured by the electromagnetic flowmeter (EMF) are affected by cathodic protection system current. Comments on the measurement results are made and precautions to be taken are proposed. Full article

(This article belongs to the Special Issue Sensors in Flow Analysis)

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195 KiB

Open AccessArticle

Influence of Different Genotypes on Trypsin Inhibitor Levels and Activity in Soybeans

by Mirjana B. Pesic, Biljana V. Vucelic-Radovic, Miroljub B. Barac, Sladjana P. Stanojevic and Viktor A. Nedovic

Sensors 2007, 7(1), 67-74; https://doi.org/10.3390/s7010067 - 24 Jan 2007

Cited by 22 | Viewed by 9014

Abstract

This study describes the relationship between the two major trypsin inhibitors (TI) in soybean, i.e., the Kunitz (KTI) and Bowman-Birk (BBI) trypsin inhibitors, as well as between them and the corresponding trypsin inhibitor activity (TIA). Twelve investigated soybean genotypes showed significant differences in [...] Read more.

This study describes the relationship between the two major trypsin inhibitors (TI) in soybean, i.e., the Kunitz (KTI) and Bowman-Birk (BBI) trypsin inhibitors, as well as between them and the corresponding trypsin inhibitor activity (TIA). Twelve investigated soybean genotypes showed significant differences in TI levels and TIA. A very strong positive correlation was found between the levels of KTI and total BBI (r = 0.94, P < 0.05). No relationship was found between KTI, BBI or total TI and TIA. Based on this data, it appears that the levels of major TI in soybean are related. Understanding the relationship between trypsin inhibitors and their activities could be useful for further improvement of the health impacts of soy proteins. Full article

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107 KiB

Open AccessArticle

A Non-invasive and Real-time Monitoring of the Regulation of Photosynthetic Metabolism Biosensor Based on Measurement of Delayed Fluorescence in Vivo

by Lingrui Zhang, Da Xing and Junsheng Wang

Sensors 2007, 7(1), 52-66; https://doi.org/10.3390/s7010052 - 24 Jan 2007

Cited by 17 | Viewed by 10085

Abstract

In this paper, a new principle biosensor for non-invasive monitoring of theregulation of photosynthetic metabolism based on quantitative measurement of delayedfluorescence (DF) is developed. The biosensor, which uses light-emitting diode lattice asexcitation light source and a compact Single Photon Counting Module to collect [...] Read more.

In this paper, a new principle biosensor for non-invasive monitoring of theregulation of photosynthetic metabolism based on quantitative measurement of delayedfluorescence (DF) is developed. The biosensor, which uses light-emitting diode lattice asexcitation light source and a compact Single Photon Counting Module to collect DF signal,is portable and can evaluate plant photosynthesis capacity in vivo. Compared with itsprimary version in our previous report, the biosensor can better control environmentalfactors. Moreover, the improved biosensor can automatically complete the measurements oflight and CO₂ response curves of DF intensity. In the experimental study, the testing of theimproved biosensor has been made in soybean (Glycine max Zaoshu No. 18) seedlingstreated with NaHSO₃ to induce changes in seedlings growth and photosynthetic metabolism.Contrast evaluations of seedlings photosynthesis were made from measurements of netphotosynthesis rate (Pn) based on consumption of CO₂ in tested plants. Current testingresults have demonstrated that the improved biosensor can accurately determine theregulatory effects of NaHSO₃ on photosynthetic metabolism. Therefore, the biosensorpresented here could be potential useful for real-time monitoring the regulatory effects ofplant growth regulators (PGRs) and other exogenous chemical factors on plant growth andphotosynthetic metabolism. Full article

(This article belongs to the Special Issue Physiological Sensing)

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254 KiB

Open AccessArticle

Improvement of Bioactive Compound Classification through Integration of Orthogonal Cell-Based Biosensing Methods

by Frank W. R. Chaplen, Ganesh Vissvesvaran, Eric C. Henry and Goran N. Jovanovic

Sensors 2007, 7(1), 38-51; https://doi.org/10.3390/s7010038 - 21 Jan 2007

Cited by 6 | Viewed by 9979

Abstract

Lack of specificity for different classes of chemical and biological agents, and false positives and negatives, can limit the range of applications for cell-based biosensors. This study suggests that the integration of results from algal cells (Mesotaenium caldariorum) and fish chromatophores (Betta splendens) [...] Read more.

Lack of specificity for different classes of chemical and biological agents, and false positives and negatives, can limit the range of applications for cell-based biosensors. This study suggests that the integration of results from algal cells (Mesotaenium caldariorum) and fish chromatophores (Betta splendens) improves classification efficiency and detection reliability. Cells were challenged with paraquat, mercuric chloride, sodium arsenite and clonidine. The two detection systems were independently investigated for classification of the toxin set by performing discriminant analysis. The algal system correctly classified 72% of the bioactive compounds, whereas the fish chromatophore system correctly classified 68%. The combined classification efficiency was 95%. The algal sensor readout is based on fluorescence measurements of changes in the energy producing pathways of photosynthetic cells, whereas the response from fish chromatophores was quantified using optical density. Change in optical density reflects interference with the functioning of cellular signal transduction networks. Thus, algal cells and fish chromatophores respond to the challenge agents through sufficiently different mechanisms of action to be considered orthogonal. Full article

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173 KiB

Open AccessArticle

Asymptotic Effectiveness of the Event-Based Sampling According to the Integral Criterion

by Marek Miskowicz

Sensors 2007, 7(1), 16-37; https://doi.org/10.3390/s7010016 - 06 Jan 2007

Cited by 61 | Viewed by 10406

Abstract

A rapid progress in intelligent sensing technology creates new interest in a development of analysis and design of non-conventional sampling schemes. The investigation of the event-based sampling according to the integral criterion is presented in this paper. The investigated sampling scheme is an [...] Read more.

A rapid progress in intelligent sensing technology creates new interest in a development of analysis and design of non-conventional sampling schemes. The investigation of the event-based sampling according to the integral criterion is presented in this paper. The investigated sampling scheme is an extension of the pure linear send-on- delta/level-crossing algorithm utilized for reporting the state of objects monitored by intelligent sensors. The motivation of using the event-based integral sampling is outlined. The related works in adaptive sampling are summarized. The analytical closed-form formulas for the evaluation of the mean rate of event-based traffic, and the asymptotic integral sampling effectiveness, are derived. The simulation results verifying the analytical formulas are reported. The effectiveness of the integral sampling is compared with the related linear send-on-delta/level-crossing scheme. The calculation of the asymptotic effectiveness for common signals, which model the state evolution of dynamic systems in time, is exemplified. Full article

(This article belongs to the Special Issue Intelligent Sensors)

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1521 KiB

Open AccessArticle

Determination of Critical Conditions for the Formation of Electrodeposited Copper Structures Suitable for Electrodes in Electrochemical Devices

by Nebojsa D. Nikolic, Konstantin I. Popov, Ljubica J. Pavlovic and Miomir G. Pavlovic

Sensors 2007, 7(1), 1-15; https://doi.org/10.3390/s7010001 - 01 Jan 2007

Cited by 56 | Viewed by 13239

Abstract

Electrodeposition of copper from acid sulfate solutions at overpotentials on theplateau of the limiting diffusion current density and at higher overpotentials wasexamined. The average current efficiencies for hydrogen evolution reaction aredetermined by a measurement of the quantity of evolved hydrogen and the overallelectrodeposition [...] Read more.

Electrodeposition of copper from acid sulfate solutions at overpotentials on theplateau of the limiting diffusion current density and at higher overpotentials wasexamined. The average current efficiencies for hydrogen evolution reaction aredetermined by a measurement of the quantity of evolved hydrogen and the overallelectrodeposition current as a function of electrodeposition time, while morphologies ofcopper deposits are examined by the use of the scanning electron microscopy (SEM)technique. It is found that the open and porous structures of copper deposits (denoted andas honeycomb – like copper structures), suitable for electrodes in electrochemical devicessuch as fuel cells and chemical sensors, were reached by electrodeposition processesfrom solutions with the lower concentrations of Cu (II) ions (0.15 M CuSO₄ and less in0.50 M H₂SO₄) at overpotentials outside the plateau of the limiting diffusion currentdensity at which the quantity of evolved hydrogen was enough to change hydrodynamicconditions in the near – electrode layer. The main characteristics of these copperstructures were craters or holes formed primarily due to the attachment hydrogen bubbleswith agglomerates of copper grains between them. Full article

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Sensors, Volume 7, Issue 1 (January 2007) – 10 articles , Pages 1-156

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