Most gases are odorless, colorless and also hazard to be sensed by the human olfactory system.
Hence, an electronic nose system is required for the gas classification process. This study presents the
design of electronic nose system using a combination of Gas Chromatography Column and a Surface
Acoustic Wave (SAW). The Gas Chromatography Column is a technique based on the compound partition
at a certain temperature. Whereas, the SAW sensor works based on the resonant frequency change. In
this study, gas samples including methanol, acetonitrile, and benzene are used for system performance
measurement. Each gas sample generates a specific acoustic signal data in the form of a frequency
change recorded by the SAW sensor. Then, the acoustic signal data is analyzed to obtain the acoustic
features, i.e. the peak amplitude, the negative slope, the positive slope, and the length. The Support
Vector Machine (SVM) method using the acoustic feature as its input parameters are applied to classify
the gas sample. Radial Basis Function is used to build the optimal hyperplane model which devided into
two processes i.e., the training process and the external validation process. According to the result
performance, the training process has the accuracy of 98.7% and the external validation process has the
accuracy of 93.3%. Our electronic nose system has the average sensitivity of 51.43 Hz/mL to sense the
gas samples.
The objective is to analyze and propose a methodology to manage with the attenuating effect promoted by carbon dioxide - CO2 on the performance of ultrasonic flow meter in gas flaring applications. Such methodology is based on experiments performed in a wind tunnel with a Reynolds number about 10^4 and concentration of CO2 above 60%. The results indicate that the ultrasonic meter exhibited measurement readings failures, especially in stages of abrupt changes in gas concentration, whose contents were above 5%. It is verified, as well, that the approximation of ultrasonic transducers tends to reduce such measurement failures.
This document discusses carbon monoxide detection using non-dispersive infrared instrumentation. It describes CO as an odorless, colorless gas that is toxic above 35 ppm. The instrument works by measuring the absorption of infrared light at 4.6 micrometers by CO molecules in a gas cell. A reference gas is generated by oxidizing CO to CO2 to eliminate interference from other gases. The analyzer provides accurate, stable measurements with automatic ranging from 0-100 ppm CO concentration.
ICP-MS is an analytical technique that combines an inductively coupled plasma source with a mass spectrometer to detect elemental ions. The ICP source converts atoms in a sample to ions at very high temperatures, which are then separated and detected based on their mass-to-charge ratio in the mass spectrometer. ICP-MS provides excellent detection limits and precision for elemental analysis and can detect many elements simultaneously while also allowing for isotopic analysis. The technique requires high vacuum and specialized components to generate the plasma, transmit ions into the mass spectrometer, separate ions by mass, and detect them.
Photonics for High-End Gas Analysis - Gasera Ltd.Gasera Ltd.
Dr. Ismo Kauppinen discusses photonics for high-end gas analysis. Key drivers for growing gas analysis needs are air pollution, global warming, and safety/security as harmful and greenhouse gases require high-sensitivity detection due to low concentrations. GASERA provides patented photoacoustic spectroscopy technology using a novel cantilever sensor that is 100x more sensitive than conventional microphones. GASERA's multi-gas analyzers and research systems have applications in life/health/environmental monitoring and security.
Method for determining exhaustion of an electrochemical gas sensorSherry Huang
A method by which an oxygen measuring instrument can test the functionality of the oxygen sensor. Oxygen sensors of the galvanic type operate by consumption of an internal easily oxidizable anode, such as lead or cadmium.
The objective is to analyze and propose a methodology to manage with the attenuating effect promoted by carbon dioxide - CO2 on the performance of ultrasonic flow meter in gas flaring applications. Such methodology is based on experiments performed in a wind tunnel with a Reynolds number about 10^4 and concentration of CO2 above 60%. The results indicate that the ultrasonic meter exhibited measurement readings failures, especially in stages of abrupt changes in gas concentration, whose contents were above 5%. It is verified, as well, that the approximation of ultrasonic transducers tends to reduce such measurement failures.
This document discusses carbon monoxide detection using non-dispersive infrared instrumentation. It describes CO as an odorless, colorless gas that is toxic above 35 ppm. The instrument works by measuring the absorption of infrared light at 4.6 micrometers by CO molecules in a gas cell. A reference gas is generated by oxidizing CO to CO2 to eliminate interference from other gases. The analyzer provides accurate, stable measurements with automatic ranging from 0-100 ppm CO concentration.
ICP-MS is an analytical technique that combines an inductively coupled plasma source with a mass spectrometer to detect elemental ions. The ICP source converts atoms in a sample to ions at very high temperatures, which are then separated and detected based on their mass-to-charge ratio in the mass spectrometer. ICP-MS provides excellent detection limits and precision for elemental analysis and can detect many elements simultaneously while also allowing for isotopic analysis. The technique requires high vacuum and specialized components to generate the plasma, transmit ions into the mass spectrometer, separate ions by mass, and detect them.
Photonics for High-End Gas Analysis - Gasera Ltd.Gasera Ltd.
Dr. Ismo Kauppinen discusses photonics for high-end gas analysis. Key drivers for growing gas analysis needs are air pollution, global warming, and safety/security as harmful and greenhouse gases require high-sensitivity detection due to low concentrations. GASERA provides patented photoacoustic spectroscopy technology using a novel cantilever sensor that is 100x more sensitive than conventional microphones. GASERA's multi-gas analyzers and research systems have applications in life/health/environmental monitoring and security.
Method for determining exhaustion of an electrochemical gas sensorSherry Huang
A method by which an oxygen measuring instrument can test the functionality of the oxygen sensor. Oxygen sensors of the galvanic type operate by consumption of an internal easily oxidizable anode, such as lead or cadmium.
Inductively coupled plasma mass spectrometryMohamed Fayed
ICP-MS has been widely used for elemental analysis in various fields such as environmental, clinical, and geological applications. It functions by inductively coupling plasma to generate ions from a sample, which are then sorted by mass and detected. Key advantages include excellent detection limits in the parts per trillion range, ability to detect multiple elements simultaneously, and capacity for isotopic analysis. The instrument features a sample introduction system that turns the sample into an aerosol, an ionization region where the plasma converts atoms into ions, ion extraction interfaces that transport ions into the mass spectrometer, and ion optics that focus the ion beam.
Graphene/PSMA composite for gas sensing applicationjournalBEEI
This paper presents the fabrication of conducting polymer sensor which comprise of graphene-poly styrene-co-maleic acid (PSMA) composite that responds to volatile organic compound (VOC) via a change in the electrical resistance of the sensors. Five sensors composed of different material ratio were fabricated to find out the most prominent weight percentage ratio (wt %) for optimum sensor response. Those materials were deposited onto silver electrode using drop-casting method. NI Card PCIE-6323 measures the voltage obtained from the sensor circuit and the resistance of the gas sensor monitored using LabVIEW instrument. It was observed from the experiments that combination of 60% graphene and 40% PSMA gives the highest sensor response.
Analysis of Damaged Floor Coverings Emissions in Indoor Air Quality with Cant...Gasera Ltd.
1) The document discusses a new photoacoustic spectroscopy technique using a cantilever sensor to detect volatile organic compounds (VOCs) emitted from damaged floor coverings.
2) This new technique allows for highly sensitive detection of VOCs like 2-ethyl-1-hexanol at the parts-per-trillion level and provides results quickly without the need for lengthy laboratory analysis.
3) The technique was tested on a floor covering sample from a building with known indoor air quality issues and was able to clearly identify the spectral signature of 2-ethyl-1-hexanol, demonstrating its potential for fast on-site emission monitoring of problem flooring.
The measurement of uric acid based on the optical absorption at visible light spectrum is investigated and tested. Sensing in the visible region was conducted for determination of suitable wavelength that produces high sensitivity and accuracy performance based on the Beer-Lambert law calculation. In this work, the uric acid is detected by detecting sodium urate as a product of chemical reaction between uric acid with sodium hydroxide buffer. The setup has been tested for uric acid concentration ranging from 15 mg/dL to 85 mg/dL. Three wavelengths have been analyzed which are 460 nm, 525 nm and 630 nm. Measured data at 460nm wavelength exhibits the highest sensitivity, which is 0.0012 (mg/dL)-with 86.51% accuracy. Detection of uric acid at visible light spectrum offers a low-cost sensor based on visible LEDs and photodiode is possible to be realized.
Measurement of Formaldehyde Pollution in Ambient AirGasera Ltd.
Formaldehyde is classified as a carcinogenic compound and until today it has been difficult to monitor with existing technologies.
The GASERA ONE FORMALDEHYDE analyzer can achieve below 1 ppb detection limit, which is well below the 16 ppb recommendation for occupational exposure limit by The National Institute for Occupational Safety and Health (NIOSH) in the USA.
* Materials updated 22 June 2017
Inductively coupled plasma - optical emission spectroscopy (ICP-OES) is an analytical technique used to detect trace metals. It uses inductively coupled plasma to excite sample atoms and ions, which then emit electromagnetic radiation at wavelengths characteristic of each element. The intensity of emission is indicative of concentration. The sample solution is nebulized and injected into the plasma where temperatures reach 6000-10000K, exciting the atoms. Emitted light is dispersed by a grating and detected, allowing element identification and quantification. ICP-OES is used for trace metal analysis in environmental, biological, food, and materials samples.
Development of-an-electronic-nose-for-fire-detection 2006-sensors-and-actuato...Allan Melvin Andrew
The document describes the development of an electronic nose using an array of eight conducting polymer sensors for fire detection. Chemical analysis of smoke from common fires identified markers that could be used to select suitable sensors. The electronic nose was able to broadly detect markers from different fire and non-fire events, as shown through principal component analysis. Initial testing suggests this e-nose technology could help reduce false alarms in fire detection.
This document discusses gas chromatography (GC) and its components. GC separates mixtures of gases using a column, carrier gas, and detector. It has three main parts: [1] a sampling mechanism that injects the gas mixture into the carrier gas stream, [2] a column where components separate due to differences in partitioning between the stationary and mobile phases, and [3] detectors that measure the concentration of each separated component. Common detectors discussed are the thermal conductivity detector, flame ionization detector, and flame photometric detector. The document also briefly discusses process gas analyzers that use techniques like near-infrared spectroscopy to continuously monitor gas concentrations.
Detection of Drugs with Cantilever-Enhanced Photoacoustic SpectroscopyGasera Ltd.
Two projects in FP7 program: CUSTOM and DOGGIES
One project in H2020 program: IRON
Measurements with hair samples.
Detection of drugs in hair.
Micro-sample studies.
Solid phase drug measurement.
FTIR-PAS measurement of cannabis.
Primary Odor on Consideration of Reducing the Number of Compositionsinventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Detection air pollution based on infrared image processingTELKOMNIKA JOURNAL
This paper proposes a method of detecting air pollution in a region using image processing techniques. The image used is the infrared image that obtained using a modified digital camera by mounting the SRS filter. Image processing technique used is to utilize wavelet transformation. Pollutants are detected based on the average number of white pixels that appear on the image. This white pixel appears due to the reflection of the wavelength of the pollutant that hits the sensor on the camera. From the results of the proposed method detection is known that the highest pollution occurs in 12.00 which is the busiest traffic time and the lowest pollution occurred in 08.00 where the traffic passing through the area has not been crowded.
The document provides information on new products from Metrohm, including:
1) The 899 Coulometer, a compact Karl Fischer titrator that can operate without a computer and includes an innovative autostart function and Ethernet connectivity for data export.
2) The Optrode sensor, a new sensor developed by Metroglas for photometric titration that has an inert glass shaft and LEDs with multiple wavelengths for measurements.
3) A new version of the Aquatrode plus ionselective electrodes for ammonia that features improvements from Metrohm.
4) New electrochemical analyzers from Metrohm Autolab that expand Metrohm's product portfolio.
The document also discusses the results of a
VG-ICP-MS combines a vapour generator, inductively coupled plasma, and mass spectrometer to analyze samples. The vapour generator converts analytes like hydrides into gas that is then ionized by the inductively coupled plasma. These ions are then separated and detected by the quadrupole mass filter. VG-ICP-MS offers advantages like measuring all samples simultaneously, achieving higher sensitivity through 100% transport efficiency to the plasma, and removing potentially interfering sample matrix components. While it provides better sensitivity and separation of interferences, it requires hydride reagents and has limitations processing samples with high salt content.
The document summarizes a hyphenated technique combining capillary electrophoresis (CE) and inductively coupled plasma mass spectrometry (ICP-MS) for elemental speciation analysis. It discusses the CE-ICP-MS instrumentation including interface designs, applications to analyze arsenic and chromium species in preserved wood and soil, and preliminary results examining interface configurations and gas flow rates.
Gas chromatography-mass spectrometry (GC-MS) is the synergistic combination of two analytical method to separate and identify different substances within a test sample.
Gas chromatography separates the components of a mixture in time.
Mass spectrometer provides information that aids in the identification and structural elucidation of each component.
This document provides information about using a spectrophotometer for quantitative analysis. It discusses how spectrophotometers work based on the Beer-Lambert law relating absorbance of light to analyte concentration. The key components of a spectrophotometer are described including the light source, wavelength selector, sample cuvette, detector, and readout device. General procedures are outlined for preparing standard solutions to generate a calibration curve and determining concentrations of unknown samples.
On data collection time by an electronic noseIJECEIAES
We use electronic nose data of odor measurements to build machine learning clas- sification models. The presented analysis focused on determining the optimal time of measurement, leading to the best model performance. We observe that the most valuable information for classification is available in data collected at the beginning of adsorption and the beginning of the desorption phase of measurement. We demonstrated that the usage of complex features extracted from the sensors’ response gives better classification performance than use as features only raw values of sensors’ response, normalized by baseline. We use a group shuffling cross-validation approach for determining the reported models’ average accuracy and standard deviation.
Asthma Identification Using Gas Sensors and Support Vector MachineTELKOMNIKA JOURNAL
The exhaled breath analysis is a procedure of measuring several types of gases that aim to
identify various diseases in the human body. The purpose of this study is to analyze the gases contained
in the exhaled breath in order to recognize healthy and asthma subjects with varying severity. An
electronic nose consisting of seven gas sensors equipped with the Support Vector Machine classification
method is used to analyze the gases to determine the patient's condition. Non-linear binary classification is
used to identify healthy and asthma subjects, whereas the multiclass classification is applied to recognize
the subjects of asthma with different severity. The result of this study showed that the system provided a
low accuracy to distinguish the subjects of asthma with varying severity. This system can only differentiate
between partially controlled and uncontrolled asthma subjects with good accuracy. However, this system
can provide high sensitivity, specificity, and accuracy to distinguish between healthy and asthma subjects.
The use of five gas sensors in the electronic nose system has the best accuracy in the classification
results of 89.5%. The gases of carbon monoxide, nitric oxide, volatile organic compounds, hydrogen, and
carbon dioxide contained in the exhaled breath are the dominant indications as biomarkers of asthma.The
performance of electronic nose was highly dependent on the ability of sensor array to analyze gas type in
the sample. Therefore, in further study we will employ the sensors having higher sensitivity to detect lower
concentration of the marker gases.
Inductively coupled plasma mass spectrometryMohamed Fayed
ICP-MS has been widely used for elemental analysis in various fields such as environmental, clinical, and geological applications. It functions by inductively coupling plasma to generate ions from a sample, which are then sorted by mass and detected. Key advantages include excellent detection limits in the parts per trillion range, ability to detect multiple elements simultaneously, and capacity for isotopic analysis. The instrument features a sample introduction system that turns the sample into an aerosol, an ionization region where the plasma converts atoms into ions, ion extraction interfaces that transport ions into the mass spectrometer, and ion optics that focus the ion beam.
Graphene/PSMA composite for gas sensing applicationjournalBEEI
This paper presents the fabrication of conducting polymer sensor which comprise of graphene-poly styrene-co-maleic acid (PSMA) composite that responds to volatile organic compound (VOC) via a change in the electrical resistance of the sensors. Five sensors composed of different material ratio were fabricated to find out the most prominent weight percentage ratio (wt %) for optimum sensor response. Those materials were deposited onto silver electrode using drop-casting method. NI Card PCIE-6323 measures the voltage obtained from the sensor circuit and the resistance of the gas sensor monitored using LabVIEW instrument. It was observed from the experiments that combination of 60% graphene and 40% PSMA gives the highest sensor response.
Analysis of Damaged Floor Coverings Emissions in Indoor Air Quality with Cant...Gasera Ltd.
1) The document discusses a new photoacoustic spectroscopy technique using a cantilever sensor to detect volatile organic compounds (VOCs) emitted from damaged floor coverings.
2) This new technique allows for highly sensitive detection of VOCs like 2-ethyl-1-hexanol at the parts-per-trillion level and provides results quickly without the need for lengthy laboratory analysis.
3) The technique was tested on a floor covering sample from a building with known indoor air quality issues and was able to clearly identify the spectral signature of 2-ethyl-1-hexanol, demonstrating its potential for fast on-site emission monitoring of problem flooring.
The measurement of uric acid based on the optical absorption at visible light spectrum is investigated and tested. Sensing in the visible region was conducted for determination of suitable wavelength that produces high sensitivity and accuracy performance based on the Beer-Lambert law calculation. In this work, the uric acid is detected by detecting sodium urate as a product of chemical reaction between uric acid with sodium hydroxide buffer. The setup has been tested for uric acid concentration ranging from 15 mg/dL to 85 mg/dL. Three wavelengths have been analyzed which are 460 nm, 525 nm and 630 nm. Measured data at 460nm wavelength exhibits the highest sensitivity, which is 0.0012 (mg/dL)-with 86.51% accuracy. Detection of uric acid at visible light spectrum offers a low-cost sensor based on visible LEDs and photodiode is possible to be realized.
Measurement of Formaldehyde Pollution in Ambient AirGasera Ltd.
Formaldehyde is classified as a carcinogenic compound and until today it has been difficult to monitor with existing technologies.
The GASERA ONE FORMALDEHYDE analyzer can achieve below 1 ppb detection limit, which is well below the 16 ppb recommendation for occupational exposure limit by The National Institute for Occupational Safety and Health (NIOSH) in the USA.
* Materials updated 22 June 2017
Inductively coupled plasma - optical emission spectroscopy (ICP-OES) is an analytical technique used to detect trace metals. It uses inductively coupled plasma to excite sample atoms and ions, which then emit electromagnetic radiation at wavelengths characteristic of each element. The intensity of emission is indicative of concentration. The sample solution is nebulized and injected into the plasma where temperatures reach 6000-10000K, exciting the atoms. Emitted light is dispersed by a grating and detected, allowing element identification and quantification. ICP-OES is used for trace metal analysis in environmental, biological, food, and materials samples.
Development of-an-electronic-nose-for-fire-detection 2006-sensors-and-actuato...Allan Melvin Andrew
The document describes the development of an electronic nose using an array of eight conducting polymer sensors for fire detection. Chemical analysis of smoke from common fires identified markers that could be used to select suitable sensors. The electronic nose was able to broadly detect markers from different fire and non-fire events, as shown through principal component analysis. Initial testing suggests this e-nose technology could help reduce false alarms in fire detection.
This document discusses gas chromatography (GC) and its components. GC separates mixtures of gases using a column, carrier gas, and detector. It has three main parts: [1] a sampling mechanism that injects the gas mixture into the carrier gas stream, [2] a column where components separate due to differences in partitioning between the stationary and mobile phases, and [3] detectors that measure the concentration of each separated component. Common detectors discussed are the thermal conductivity detector, flame ionization detector, and flame photometric detector. The document also briefly discusses process gas analyzers that use techniques like near-infrared spectroscopy to continuously monitor gas concentrations.
Detection of Drugs with Cantilever-Enhanced Photoacoustic SpectroscopyGasera Ltd.
Two projects in FP7 program: CUSTOM and DOGGIES
One project in H2020 program: IRON
Measurements with hair samples.
Detection of drugs in hair.
Micro-sample studies.
Solid phase drug measurement.
FTIR-PAS measurement of cannabis.
Primary Odor on Consideration of Reducing the Number of Compositionsinventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Detection air pollution based on infrared image processingTELKOMNIKA JOURNAL
This paper proposes a method of detecting air pollution in a region using image processing techniques. The image used is the infrared image that obtained using a modified digital camera by mounting the SRS filter. Image processing technique used is to utilize wavelet transformation. Pollutants are detected based on the average number of white pixels that appear on the image. This white pixel appears due to the reflection of the wavelength of the pollutant that hits the sensor on the camera. From the results of the proposed method detection is known that the highest pollution occurs in 12.00 which is the busiest traffic time and the lowest pollution occurred in 08.00 where the traffic passing through the area has not been crowded.
The document provides information on new products from Metrohm, including:
1) The 899 Coulometer, a compact Karl Fischer titrator that can operate without a computer and includes an innovative autostart function and Ethernet connectivity for data export.
2) The Optrode sensor, a new sensor developed by Metroglas for photometric titration that has an inert glass shaft and LEDs with multiple wavelengths for measurements.
3) A new version of the Aquatrode plus ionselective electrodes for ammonia that features improvements from Metrohm.
4) New electrochemical analyzers from Metrohm Autolab that expand Metrohm's product portfolio.
The document also discusses the results of a
VG-ICP-MS combines a vapour generator, inductively coupled plasma, and mass spectrometer to analyze samples. The vapour generator converts analytes like hydrides into gas that is then ionized by the inductively coupled plasma. These ions are then separated and detected by the quadrupole mass filter. VG-ICP-MS offers advantages like measuring all samples simultaneously, achieving higher sensitivity through 100% transport efficiency to the plasma, and removing potentially interfering sample matrix components. While it provides better sensitivity and separation of interferences, it requires hydride reagents and has limitations processing samples with high salt content.
The document summarizes a hyphenated technique combining capillary electrophoresis (CE) and inductively coupled plasma mass spectrometry (ICP-MS) for elemental speciation analysis. It discusses the CE-ICP-MS instrumentation including interface designs, applications to analyze arsenic and chromium species in preserved wood and soil, and preliminary results examining interface configurations and gas flow rates.
Gas chromatography-mass spectrometry (GC-MS) is the synergistic combination of two analytical method to separate and identify different substances within a test sample.
Gas chromatography separates the components of a mixture in time.
Mass spectrometer provides information that aids in the identification and structural elucidation of each component.
This document provides information about using a spectrophotometer for quantitative analysis. It discusses how spectrophotometers work based on the Beer-Lambert law relating absorbance of light to analyte concentration. The key components of a spectrophotometer are described including the light source, wavelength selector, sample cuvette, detector, and readout device. General procedures are outlined for preparing standard solutions to generate a calibration curve and determining concentrations of unknown samples.
On data collection time by an electronic noseIJECEIAES
We use electronic nose data of odor measurements to build machine learning clas- sification models. The presented analysis focused on determining the optimal time of measurement, leading to the best model performance. We observe that the most valuable information for classification is available in data collected at the beginning of adsorption and the beginning of the desorption phase of measurement. We demonstrated that the usage of complex features extracted from the sensors’ response gives better classification performance than use as features only raw values of sensors’ response, normalized by baseline. We use a group shuffling cross-validation approach for determining the reported models’ average accuracy and standard deviation.
Asthma Identification Using Gas Sensors and Support Vector MachineTELKOMNIKA JOURNAL
The exhaled breath analysis is a procedure of measuring several types of gases that aim to
identify various diseases in the human body. The purpose of this study is to analyze the gases contained
in the exhaled breath in order to recognize healthy and asthma subjects with varying severity. An
electronic nose consisting of seven gas sensors equipped with the Support Vector Machine classification
method is used to analyze the gases to determine the patient's condition. Non-linear binary classification is
used to identify healthy and asthma subjects, whereas the multiclass classification is applied to recognize
the subjects of asthma with different severity. The result of this study showed that the system provided a
low accuracy to distinguish the subjects of asthma with varying severity. This system can only differentiate
between partially controlled and uncontrolled asthma subjects with good accuracy. However, this system
can provide high sensitivity, specificity, and accuracy to distinguish between healthy and asthma subjects.
The use of five gas sensors in the electronic nose system has the best accuracy in the classification
results of 89.5%. The gases of carbon monoxide, nitric oxide, volatile organic compounds, hydrogen, and
carbon dioxide contained in the exhaled breath are the dominant indications as biomarkers of asthma.The
performance of electronic nose was highly dependent on the ability of sensor array to analyze gas type in
the sample. Therefore, in further study we will employ the sensors having higher sensitivity to detect lower
concentration of the marker gases.
Comparison of signal smoothing techniques for use in embedded system for moni...Dalton Valadares
Paper about the comparison between some signal smoothing techniques for use in an embedded system responsible for monitoring the biofuels quality, specificaly the oxidative stability.
Concentration measurements of bubbles in a water column using an optical tomo...ISA Interchange
Optical tomography provides a means for the determination of the spatial distribution of materials with different optical density in a volume by non-intrusive means. This paper presents results of concentration measurements of gas bubbles in a water column using an optical tomography system. A hydraulic flow rig is used to generate vertical air–water two-phase flows with controllable bubble flow rate. Two approaches are investigated. The first aims to obtain an average gas concentration at the measurement section, the second aims to obtain a gas distribution profile by using tomographic imaging. A hybrid back-projection algorithm is used to calculate concentration profiles from measured sensor values to provide a tomographic image of the measurement cross-section. The algorithm combines the characteristic of an optical sensor as a hard field sensor and the linear back projection algorithm.
This document summarizes a presentation on electronic noses. It begins with an introduction comparing biological noses to electronic noses. The need for electronic noses is that they are faster, more reliable, and can detect hazardous gases that humans cannot. The basic design of an electronic nose involves pulling a gas sample through a sensor array to produce response signals. Common sensor technologies are described along with the sample delivery, detection, and computing systems of electronic noses. Applications discussed include medical diagnosis, environmental monitoring, food quality control, and explosive detection. In conclusion, while electronic noses are cheaper and faster than biological noses, they still cannot match the sensitivity and selectivity of mammalian noses.
Vu Anh Minh QCM - nano tech -1 s2 0-s0169433212019861-main(3)Minh Vu
This document describes research into enhancing the ammonia (NH3) gas sensing properties of a quartz crystal microbalance (QCM) sensor by increasing the length of vertically oriented zinc oxide (ZnO) nanorods on the sensor. ZnO nanorods of varying lengths were grown on the QCM sensor using a hydrothermal method. The length of the nanorods increased from 1200 nm to 3000 nm as the growth time increased from 1 to 4 hours. Testing of the sensors found that sensors with longer ZnO nanorods exhibited greater shifts in resonant frequency when exposed to NH3 gas concentrations ranging from 50 to 800 ppm, indicating enhanced sensing response from the increased nanorod length and corresponding surface area.
Quartz crystal microbalance based electronic nose system implemented on Field...TELKOMNIKA JOURNAL
1) The document describes a quartz crystal microbalance (QCM) based electronic nose system implemented on a field programmable gate array (FPGA).
2) The electronic nose uses an array of 8 QCM sensors coated with different chemicals and measures their frequency changes when exposed to gases.
3) A neural network with 8 input nodes, 10 hidden nodes, and 2 output nodes is used for pattern recognition on the FPGA. The sigmoid activation function is approximated using a second order equation to simplify hardware implementation.
Varying Effects of Temperature and Path-length on Ozone Absorption Cross-sectionTELKOMNIKA JOURNAL
Inconsistencies in the absorption cross section of ozone have been observed. Hence, for accurate measurement, we have reported the combined effects of varying optical path-length and temperature on the ozone gas absorption cross section (OACS) at 334.15nm. Adopting optical absorption spectroscopy, results of the (OACS) have been simulated using spectralcalc simulator with HITRAN 12 has the latest line list. OACS increased by 52.27% as the temperature increased from 100K to 350K while it was slightly affected by a 0.007% decrease varying the path-length from 0.75cm-130cm.
The high demand of meat causes the seller mix the fresh and not-fresh meat. Electronic nose was used to detect the quality of the meat quickly and accurately. This research is proposed to test and analyze the sensitivity of MOS sensor in the electronic nose and simulate it using Matlab to identify meat classification using neural network. Test parameters based on Indonesian National Standard (SNI 3932-2008) requirement on the quality of carcass and meat. In this simulation, the number of neurons in the hidden layer was varied to find the most accurate identification. The sensitivity analysis of the MOS sensor was conducted by testing the meat sample aroma, calculate the sensitivity, identify the formation of input, hidden layer, outputs, and simulate the result of the varied formation. Then, found the number of the most optimal neurons. The result of the data training will be applied to the real instrument.
This document summarizes a research study that examined the use of a metal oxide semiconductor pellet sensor for detecting components of exhaled breath. Specifically, it fabricated a pellet sensor using a mixture of zinc oxide and tin oxide nanopowders. It characterized the sensor's electrical conductivity, sensitivity, response time and recovery time when exposed to exhaled breath and individual exhaled breath components at room temperature. The study found that the pellet sensor's electrical conductivity decreases when exposed to exhaled breath, and that it responds differently to different exhaled breath components. The pellet sensor shows potential for use in disease detection or quantification of exhaled breath components through non-invasive breath analysis.
International Journal of Engineering Research and DevelopmentIJERD Editor
This document describes the development of a prototype pipe tracking robot that uses electronic nose technology to detect gas leaks. The robot is designed to automatically track and follow pipes using ultrasonic sensors. It also uses an MQ6 gas sensor to detect the presence of gas leaks, identify the type of gas, and transmit sensor data to an Arduino microcontroller and LCD display. The researchers tested the prototype's ability to track a PVC pipe, detect different gases, and display detection information. Test results showed the robot could successfully track a 10 cm diameter pipe from 5 cm away and detect gas leaks within 1 minute. The LCD also correctly displayed gas detection information.
Neuro identification of some commonly used volatile organic compounds using e...Alexander Decker
This document describes a study that used an electronic nose system with three gas sensors and an artificial neural network to identify three volatile organic compounds (formaldehyde, acetone, and chloroform). Sensor responses were analyzed and 60% of data was used to train the neural network, which successfully identified the compounds. The system has potential for applications in environmental monitoring and industrial process control.
This presentation provides an overview of electronic noses (e-noses). It discusses how e-noses can detect volatile organic compounds to identify odors, similar to biological noses but with advantages like not tiring, getting sick, or being distracted. The main components of an e-nose include a sample delivery system to introduce odors, a sensor array to transduce chemical interactions into electrical signals, and a computing system to analyze the sensor responses. Common sensor technologies are metal oxide sensors, conducting polymers, quartz crystal microbalances, and MOSFETs. E-noses find applications in medical diagnosis, environmental monitoring, the food industry, and detecting explosives. Future areas of research include miniaturizing e-nose technology and
Nanocrystalline graphite humidity sensors for wearable breath monitoring appl...Conference Papers
This document summarizes research on a nanocrystalline graphite humidity sensor fabricated using plasma enhanced chemical vapor deposition. The sensor shows fast response times to changes in humidity, such as those caused by human breath. It is also durable against contaminants like sweat or saliva. The sensor is small and could be integrated into a wearable smart mask to continuously monitor breath humidity for health applications. Experimental results show the sensor resistance decreases sharply during exhalation and recovers during inhalation, demonstrating its ability to detect changes in breath humidity.
Flow Field Measurements in a Large Controlled Ventilated RoomIRJET Journal
This document summarizes research measuring air flow fields in a large controlled ventilated test room. Laser Doppler Velocimetry was used to measure three-dimensional velocity fields at 690 points under two air flow rates, corresponding to 15 and 30 air changes per hour. The measurements characterized the overall air flow patterns, which involved air exiting ceiling inlets, descending toward the floor then circulating back up and toward exhaust grids. Increasing the air flow rate resulted in higher measured velocities but similar overall circulation patterns. The non-intrusive velocity measurements provide data to validate computational fluid dynamics simulations of air flow in ventilated spaces.
This is ppt for students of colleges for various exams.RockeyKumar5
This document proposes a study of ZnO nanoparticles for gas sensing applications. The objectives are to synthesize and characterize ZnO nanoparticles using hydrothermal and other chemical methods. Characterization would include structural and optical properties analysis using XRD, SEM, TEM, FTIR, and UV-Vis spectroscopy. Gas sensing response, selectivity and sensitivity would be determined for various pollutants using the nanoparticles. Computational simulation using software like Siesta and DFT would validate adsorption-desorption mechanisms when ZnO is exposed to gases. The expected outcomes are a robust gas sensor with high response, low detection limits, and mathematical models to optimize sensitivity and selectivity.
This document describes the development of a low-cost adjustable gaseous exhaust analyzer for runtime characterization of vehicle emissions. The analyzer uses a telescopic tube arrangement to passively control exhaust temperature for different sensor needs. It can monitor CO, NOx, CO2, and humidity concentrations in real-time. The analyzer was validated against commercial instruments, showing results within 20% error. Future work will incorporate flow sensors and monitor additional gases to allow for a more complete emissions analysis.
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
This document describes using a snake optimization algorithm to tune the gains of an enhanced proportional-integral controller for congestion avoidance in a TCP/AQM system. The controller aims to maintain a stable and desired queue size without noise or transmission problems. A linearized model of the TCP/AQM system is presented. An enhanced PI controller combining nonlinear gain and original PI gains is proposed. The snake optimization algorithm is then used to tune the parameters of the enhanced PI controller to achieve optimal system performance and response. Simulation results are discussed showing the proposed controller provides a stable and robust behavior for congestion control.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
Adaptive segmentation algorithm based on level set model in medical imagingTELKOMNIKA JOURNAL
For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
Automatic channel selection using shuffled frog leaping algorithm for EEG bas...TELKOMNIKA JOURNAL
Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
2. ISSN: 1693-6930
TELKOMNIKA Vol. 16, No. 4, August 2018: 1458-1467
1458
and QCM work based on the resonant frequency change. In the analytical approximation,
Sauerbrey’s formula presented in Equation 1 is widely used to determine the change of
resonant frequency affected by the absorbed mass on the crystal’s surfaces [11]:
2
02F
F m
A
(1)
where ∆F is the change of resonant frequency (Hz), F0 is the resonant frequency (Hz), ∆m is
the mass change (g), A is the active crystal area (cm2
), ρ is the crystal density (g/cm3
), and μ is
the shear modulus of the crystal (g/cms2
).
In 2014, Hari Agus Sujono et al., applied QCM sensor arrays for vapor identification
system which has the resonant frequency of 20 MHz [9]. This type of sensor array induces the
complex configuration and the interference issues. Therefore, only a single sensor of SAW will
be used to sense the odor which has the resonant frequency of 34 MHz. The SAW sensor used
in this experiment operates at a higher resonant frequency. Hence it affects the increase in
sensitivity because the change of the resonant frequency (∆F) to sense the mass change
absorbed by crystal area for both sensors are dependent on their resonant frequency (F0) as
explained by Sauerbrey’s formula.
To achieve a good selectivity in the electronic nose system, we applied a Gas
Chromatography (GC) principle for the compound analysis. The GC is a technique based on the
compound partition at a certain temperature which involves the two phases, i.e., the stationary
phase and the mobile gas phase. The stationary phase material is located in the
chromatography column as the partition material, whereas the mobile gas phase consists of a
sample carried by dry air into the partition column [12]. Each sample has different elution
strength because of the polarity suitability with the stationary phase material in the partition
column [13]. In 2016, the electronic nose system by integrating GC and TGS sensor was
conducted by Radi et al. [12]. However, the TGS sensor has a low sensitivity which requires the
high amount of concentration for the measurement. Therefore, in this study, a combination
between GC and SAW sensor in the electronic system is expected to overcome the issues.
For the recognition part in the electronic system, we used a learning algorithm of
Support Vector Machine (SVM) for the classification process. The SVM is proposed as an
effective technique for data classification. It is derived from statistical learning theory introduced
by Vladimir Vapnik et al. [14]. Basically, another competitive learning algorithm is Artificial
Neural Network (ANN), both of them are included in the supervised learning classifier [15].
However, many researchers reported that SVM classifier often outperforms than the ANN
classifier [16]. The ANN classifier achieves an optimal local solution, while the SVM classifier
obtains an optimal global solution. It is not surprising that the solution of the ANN classifier is
different for each training process which results in a different optimal solution, whereas the
solution offered by SVM classifier is same for every running. Hence, it generates the same
optimal solution [17-19]. The contents of this paper are organized as follows: section 2
discusses the experimental design of the electronic nose system, feature extraction, and
elaborate the SVM classifier technique. Furthermore, section 3 demonstrates the results and
verification analysis. Finally, we present our conclusion in section 4.
2. Research Method
2.1. The Experimental Design
In this study, the experimental design of the electronic nose system includes four main
parts, i.e., a gas sample, a GC column, a detector, and data analysis. Three types of gas
samples were used in this study, i.e., methanol, acetonitrile, and benzene. The chromatography
column consisted of Thermon-3000 and ShinCarbon as the stationary phase material. The SAW
device which has the resonant frequency of 34 MHz was used as the detector to record the
frequency change of the acoustic signal generated by each gas sample.
2.2. The Experimental Procedure
Figure 1 presents the design of our electronic nose system. The experimental setup is
depicted in Figure 1a, whereas the schematic layout is shown in Figure 1b. There are three
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main parts of our design, i.e. the carrier gas, the chromatography column, and the SAW sensor.
The dry air is used to carry the gas samples of A (methanol), B (acetonitrile), and C (benzene).
The chromatography column is made of the glass material with the diameter of 3.2 mm and the
length of 1.6 m. It has the operating temperature value above 70o
C. The chamber as the oven
wherein the chromatography column located is made of the aluminum with the geometrical size
of 40 cmx7.5 cmx8 cm.
(a)
(b)
Figure 1. The design of electronic nose system: (a) the experimental setup,
(b) the schematic layout
Before starting the measurement, the chromatography column is needed to be cleaned
for 30 minutes using the carrier gas pushed by the air pump. The amounts odor volumes of 20
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mL gas sample are introduced into the injection port. Then the gas sample is transported by the
carrier gas into the chromatography column which is located in a chamber operated under the
controlled temperature of 800
C. Interactions between stationary phase material and the gas
sample compound generate a series of fractions which is converted by the SAW sensor as the
acoustic frequency change data. Furthermore, the acoustic signal data are transmitted to the
computer through the Frequency Counter (FC) device for the data analysis. According to the
measurement, the SAW sensor records the frequency value of about 34 MHz at initial condition
before injecting the gas sample. The frequency change is described as
( ) .reff f t f (2)
where ∆f is the frequency change, fref is the initial frequency of 34 MHz, and f(t) is detected
frequency after injecting the gas sample. Furthermore, to collect the acoustic signal data
produced by each gas sample needs 500 seconds. Figure 2 shows the sensor response to the
acetonitrile.
Figure 2. The sensor response to the gas sample of acetonitrile
2.3. Feature Extraction of Acoustic Signal Processing
In this study, the acoustic signal data would be processed to obtain the acoustic
features. Figure 3 describes the parameters included to determine the acoustic features using
the threshold of -100 Hz value. The four acoustic features including the peak amplitude Ap,
the negative slope S(-)
, the positive slope S(+)
, and the length L are used in this study determined
in Equation 3,4,5 and 6 respectively:
Figure 3. Acoustic feature parameters
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p pA y (3)
( ) p f
p r
y y
S
t t
(4)
( ) r p
r p
y y
S
t t
(5)
r fL t t (6)
where tf is the fall time, yf is the fall amplitude, tp is the peak time, yp is the peak amplitude, tr is
the rise time, and yr is the rise amplitude.
2.4. Support Vector Machine (SVM) Classifier
In this study, we used the SVM classifier to identify the gas type which included four
acoustic features as the input parameters. The gas types are divided into three classes. To
understand the basic principle of SVM classifier, the simple linear separable case is shown in
Figure 4. In the original space, a linear hyperplane f(x) is used to separate the data points
according to the support vector position. Hence, the linear hyperplane f(x) groups the data
points into two classes, i.e., class +1 and class -1 which are constrained by f(x) +1 and
f(x) +1, respectively [20]. However, many real cases contain noise or outlier data points which
are non-linearly separable [21]. Thus, the main objective of the SVM classifier is to obtain the
optimal hyperplane model that can maximize the margin (M) of the classes [22].
Figure 4. The Linear separable case using SVM method
The SVM classifier includes the kernels to optimize the hyperplane model for a
nonlinear separable case. The kernels allow transforming the data points into a higher
dimensional space called feature space to obtain a linear hyperplane although occasionally
result in a nonlinear hyperplane in the original space. In this study, we used Radial Basis
Function (RBF) as the kernel function. The RBF kernel is derived in Equation 7. Then the
hyperplane model f(xd) is determined in Equation 8 [23,24].
2
( , ) exp( )i d i d H x x x x
(7)
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1
( ) ( , )
n
d i i i d
i
f y b
x H x x
(8)
where xd is the data point, α is lagrange multiplier, yi is membership of the gas sample class, γ
is gamma, xi is support vector, b is intercept, and i = 1, 2, 3, . . . , n.
It is broadly mentioned that the SVM classifier using RBF kernel requires the best
combination of two hyperparameters, i.e., gamma (γ) and cost (c) to build the optimal
hyperplane model. The gamma explains how significant the influence of each data point in the
training set. For example, a higher value of gamma leads the over-fitting problem because it
tries to fit exactly each data point in the training set. Whereas, the cost is used to control the
trade-off between smooth decision boundary and classifying the data points in the training set
correctly [25,26].
In this study, the identification gas system using SVM classifier consisted of two
processes, i.e. the training process and the external validation process. The training process
was used to build the hyperplane model which included the acoustic signal data from the total
numbers of 150 gas samples. Since the external validation process was used to assess the
SVM performance. It used the acoustic signal data obtained from the total numbers of 30 gas
sample measurements.
To describe the performance analysis of the SVM classifier, the 3x3 confusion matrix
table was applied for this study, shown in Table 1 [27]. In the confusion matrix table, the actual
result is the data based on the observation (reality). It is consisted of three classes i.e., class A,
B, and C, whereas the predicted result is the identification result assessed by the SVM classifier
which also consisted of three classes. The cases are divided into nine values: TA, FA1, FA2,
FB1, TB, FB2, FC1, FC2, and TC. Finally, the accuracy (AC) used to assess the SVM
performance to classify gas sample is determined in Equation 9 [28].
Table 1. The 3x3 confusion matrix
Actual Result
A B C
Predicted
Result
A TA FA1 FA2
B FB1 TB FB2
C FC1 FC2 TC
100%
1 2 1 2 1 2
T
AC
T FA FA FB FB FC FC
(9)
where T TA TB TC ,TA is the correctly classified class A, TB is the correctly classified class
B, TC is the correctly classified class C, FA1 is the class B classified into class A, FA2 is the
class C classified into class A, FB1 is the class A classified into class B, FB2 is the class C
classified into class B, FC1 is the class A classified into class C, FC2 is the class B classified
into class C.
3. Results and Analysis
In this study, we designed the electronic nose system which concerns into two terms,
i.e., having high sensitivity and good repeatability. Figure 5 shows the measurement result of
the signal acoustic data recorded by the electronic nose system. Based on the Equation 2, each
gas sample has the specific frequency change (∆f) curve affected by each gas sample's mass
absorbed by crystal area of SAW sensors. In the term of sensitivity, according to Figure 5a by
using 5 mL odor volume, the amplitude peak determined in equation 3 from gas sample A, B,
and C are -2000 Hz, -1000 Hz, and -85 Hz, respectively.
Furthermore, by applying 20 mL odor volumes, the gas sample A, B, and C reach the
amplitude peak of -2800 Hz, -1750 Hz, and -850 Hz, respectively. It means that the electronic
nose system could sense the odor from methanol, acetonitrile, and benzene with the sensitivity
of 53.3 Hz/mL, 50 Hz/mL, and 51 Hz/mL, respectively. Hence the average sensitivity is 51.43
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Hz/mL. Rivai et al. [29,30] have designed the electronic nose using gas chromatography and
QCM sensor. According to the result performance, it has the approximate sensitivity of 6.5
Hz/mL to sense the odor of ethanol. Another research paper shows that the frequency change
curve resulted by specific odor, fragrance, and gas in the range of hundreds herzt [31]. Our
system offers higher operating resonant frequency. Hence, it is able to generate the specific or
distinctive acoustic signal coming from each gas sample in the range of thousands hertz, shown
in Figure 5.
(a) (b)
Figure 5. The acoustic signal data affected by the odor volume of (a) 5 mL, and (b) 20 mL
In the term of repeatability, each gas sample compound produces a specific acoustic
signal data because it has particular interactions with stationary phase material in the
chromatography column. The main difference of each gas sample curve is pointed out by its
peak amplitude Ap. For example, in Figure 5a, the highest peak amplitude is achieved by gas
sample C. The gas sample A has the lowest value of amplitude peak and these trends are
repeated in Figure 5b when using the amounts odor volumes of 20 mL. Furthermore, the
acoustic signal data generated by each gas sample are processed to obtain the four acoustic
features.
Figure 6 presents the distribution of four acoustic features i.e., the peak amplitude Ap,
the negative slope S(-)
, the positive slope S(+)
, and the length L which refer to Equation 3, 4, 5,
and 6 respectively. The distribution result given by Figure 6 includes 50 measurements using 20
mL odor volumes. The distribution results of the peak amplitude Ap, the negative slope S(-)
, the
positive slope S(+)
, and the length L can be seen in Figure 6a, 6b, 6c, and 6d sequentially. As
shown in Figure 6a, 6b, 6c, and 6d, we can conclude that the distribution of the acoustic
features from gas sample A, B, and C are classified into the non-linearly separable case.
(a) (b)
Figure 6. The acoustic features of gas sample: (a) the peak amplitude, (b) the negative slope.
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(c) (d)
Figure 6. The acoustic features of gas sample: (c) the positive slope, (d) the length
The recognition algorithm of SVM classifier was used to solve the non-linearly
separable case. In this study, the total numbers of 150 gas samples were used for training
process to build the optimal hyperplane model using RBF kernel. The RBF kernel requires the
best combination of two hyperparameters of gamma and cost. In the hyperparameters tuning,
we set the interval of gamma started from 2-15
to 22
, whereas the cost has the lower limit of 2-15
and the upper limit of 0.25. Figure 7 presents the detail distribution of the hyperparameter tuning
performance. The dark blue color (left) and the dark green color (right) have the lowest and
highest accuracy, respectively. According to the training process, the best combinations of
gamma and cost are 1 and 0.2, respectively, which have the accuracy of 98.7%. It means the
total numbers of 150 observations used for the training process: 148 data are correctly
classified and the others are incorrectly classified.
Figure 7. The hyperparameters tuning performance
The external validation was used for the testing to assess the SVM classifier
performance. It included the acoustic signal data from 30 gas samples (10 data for each gas
sample). Table 2 shows the confusion matrix result from external validation process. The result
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of case TA, FA1, FA2, FB1, TB, FB2, FC1, FC2, and TC are 9, 1, 0, 1, 9, 0, 0, 0, and 10,
respectively. The SVM classifier has the accuracy of 93.3% to identify the gas sample, which
means from the total numbers of 30 observations used for the external validation process: 28
correctly classified and 2 incorrectly classified. These results indicate that the SVM classifier
can be categorized as the robust algorithm which can be integrated with the electronic nose
system.
Table 2. The 3x3 confusion matrix result
Actual Result
A B C
Predicted
Result
A 9 1 0
B 1 9 0
C 0 0 10
4. Conclusion
The design of the electronic nose system with good repeatability and high sensitivity by
integrating the gas chromatography principle and Surface Acoustic Wave (SAW) sensor was
successfully demonstrated. Three gas samples were used for the measurement process, i.e.,
methanol, acetonitrile, and benzene. In the previous research, the electronic nose using gas
chromatography and QCM sensor has only the approximate sensitivity of 6.5 Hz/mL to sense
the odor. Another research also shows that the frequency change curve resulted by specific
odor, fragrance, and gas only in the range of hundreds herzt. Based on the result analysis, our
electronic nose system has the average sensitivity of 51.43 Hz/mL and also offers higher
operating resonant frequency. Hence, it is able to generate more specific or distinctive acoustic
signal coming from each gas sample.
The repeatability performance is shown by the distinctive acoustic signal curve from
each gas sample due to the specific interactions between the odor and the material located in
the chromatography column. In this study, Support Vector Machine using Radial Basis Function
was applied to recognize the odor. The four acoustic features obtained from acoustic signal data
were used for input parameters in the classifier, i.e., the amplitude peak, the negative slope, the
positive slope, and the length. The classification using Support Vector Machine was divided into
two processes, i.e., the training process and the external validation process. The training
process and the external validation process have the high accuracy of 98.7% and 93.3%,
respectively. These results indicate that the classifier can be applied to the electronic nose
system. Finally, to achieve the comprehensive result performance, the future work will concern
on a deep investigation of sensitivity and repeatability performances at the electronic nose
system by varying the temperature of the chamber, the pressure of the air pump, and different
type kernel functions in the Support Vector Machine algorithm.
Acknowledgment
This research was carried out with financial aid support from the Ministry of Research,
Technology and Higher Education of The Republic of Indonesia (Kemenristekdikti RI).
The authors also would like to acknowledge LPPM ITS for the intense discussion.
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